Read each sentence to find out whether there is any error in any part. Select the part that contains an error, or choose No error if the sentence is grammatically correct: The boy s parents pleaded with the Principal that they were too poor to pay his tuition fee.

Introduction / Context:
This error detection question presents a sentence that appears slightly awkward at first glance, and you must decide whether there is any grammatical mistake in any part. The sentence describes the parents of a boy speaking to the Principal about their inability to pay the tuition fee. The challenge is to distinguish between slightly formal but acceptable structures and genuinely incorrect grammar.

Given Data / Assumptions:
- Part a: The boy s parents.
- Part b: pleaded with the Principal.
- Part c: that they were too poor to pay his tuition fee.
- Part d: No error.
- The context is a polite request made to a school Principal regarding fees.

Concept / Approach:
In English, the verb plead can be followed either by with plus a person or by that plus a clause, depending on the structure. In this sentence, we have pleaded with the Principal that they were too poor to pay his tuition fee. This combines both patterns but remains grammatically acceptable in formal reported speech, because the that clause explains the content of their plea. The pronouns they and his are also acceptable, since they refers to the parents and his to the boy. Therefore, although the sentence is somewhat long, it does not actually violate standard grammar rules and is treated as correct in exam keys.

Step-by-Step Solution:
Step 1: Examine part a and confirm that The boy s parents correctly expresses whose parents they are.
Step 2: Check part b, pleaded with the Principal, and note that plead with someone is a valid and common pattern.
Step 3: Look at part c, that they were too poor to pay his tuition fee, and recognise this as a that clause giving the reason for their plea, which is acceptable in this context.
Step 4: Since no part contains a clear grammatical error, select Part d, No error, as the answer.

Verification / Alternative check:
Read an alternative but equally correct version of the sentence: The boy s parents pleaded with the Principal that they were too poor to pay his tuition fee. Many standard grammar explanations accept this combination of pleaded with and a that clause, because the with phrase specifies whom they addressed and the that clause reports what they said. The overall tense sequence and pronoun reference are consistent and clear, so the sentence functions properly in formal English.

Why Other Options Are Wrong:
- Part a: correctly identifies the parents by referring to the boy; there is no error in number or case.
- Part b: uses pleaded with the Principal, which is an acceptable verb preposition combination.
- Part c: properly introduces a reason clause with that they were too poor to pay his tuition fee and maintains correct tense and pronoun use.
- Part e suggesting errors in more than one part is clearly incorrect, because we have not found any genuine grammatical violation in any section.

Common Pitfalls:
Many candidates feel uneasy about combining pleaded with and a that clause and therefore assume there is an error. However, exam questions sometimes include sentences that are fully correct to test whether you can confidently choose No error instead of forcing a correction. A good strategy is to check subject verb agreement, preposition use, pronoun reference, and tense consistency systematically. If all of these are in order, it is often safe to accept the sentence as correct even if the wording feels slightly formal or old fashioned.

Final Answer:
The sentence is grammatically correct, so the right choice is Part d: No error.