In this sentence-improvement question on advanced grammar, choose the correct option about whether the highlighted phrase "has not been profitable for them to do so" needs any correction in the sentence "The political masters of health care system have not listened to professional health planners because it has not been profitable for them to do so."

Introduction / Context:
This question tests your ability to judge whether a complex sentence is already grammatically correct or whether a suggested alternative phrase is better. The sentence is: "The political masters of health care system have not listened to professional health planners because it has not been profitable for them to do so." The phrase in bold is "has not been profitable for them to do so". You are also given three alternative phrases (i, ii, iii). You must decide whether any of these should replace the bold phrase or whether the original phrase requires no correction at all.

Given Data / Assumptions:

• Original phrase: "has not been profitable for them to do so".
• Option (i): has not been profitable for them to do that things.
• Option (ii): has been unprofitable for the professionals to do so.
• Option (iii): has been not profitable for them to do so.
• The subject "it" refers to the act of listening to professional health planners.
• The pronoun "them" refers to the political masters of the health care system.

Concept / Approach:
We must check the original phrase for correctness in grammar, clarity, and reference. "It has not been profitable for them to do so" is a perfectly acceptable construction in standard English. It employs a clear subject ("it"), the present perfect tense ("has not been"), and an infinitive phrase ("for them to do so") that correctly indicates that listening has not yielded profit for the political masters. We then examine the suggested alternatives and check whether they improve or damage correctness and meaning. If none of the alternatives are acceptable, we conclude that no correction is required.

Step-by-Step Solution:
Step 1: Read the original sentence: "The political masters of health care system have not listened to professional health planners because it has not been profitable for them to do so." Step 2: Confirm that "it" refers back to the act of listening to professional health planners, and "for them" correctly refers to the political masters. Step 3: Observe that "has not been profitable" is a correct present perfect passive-like structure indicating that in the past up to now, listening has not given profit. Step 4: Examine option (i) "has not been profitable for them to do that things" – this is clearly ungrammatical because "that things" is wrong; it should be "those things". Step 5: Examine option (ii) "has been unprofitable for the professionals to do so" – this changes the meaning by suggesting that it is unprofitable for the professionals, not the political masters, which is not intended. Step 6: Examine option (iii) "has been not profitable for them to do so" – the word order is awkward; standard English prefers "has not been profitable". Step 7: Conclude that none of the alternatives improve the sentence, and therefore "No correction required" is the correct choice.

Verification / Alternative check:
You can verify by rephrasing the original sentence in simpler words: "The political leaders have ignored professional health planners because listening to them has not been profitable for the leaders." This rephrasing clearly matches the original meaning and shows that the grammar of the original phrase is sound. No change in tense, subject reference, or structure is necessary. Each suggested alternative either introduces a new grammatical mistake or shifts the meaning away from the intended subject, which is the political masters, not the professionals.

Why Other Options Are Wrong:
Option (i) contains the phrase "that things", which is grammatically incorrect. It should be either "those things" or a singular form, and it still would not add clarity. Option (ii) wrongly shifts the focus to the professionals by saying it is unprofitable for them, which changes the meaning of the sentence. Option (iii) uses an unnatural word order "has been not profitable", whereas natural English says "has not been profitable".

Common Pitfalls:
Many students think that because alternatives are offered, one of them must be better. This leads them to change a sentence that is already correct. In sentence-improvement questions, always remember that "No correction required" is a valid and often the correct option. Carefully examine the original sentence for actual mistakes before assuming a change is needed. Also, pay attention when the alternatives shift the meaning by changing the subject or the pronoun reference; such subtle changes make them unsuitable replacements.

Final Answer:
The original phrase is already correct, so the answer is No correction required.