In the sentence "The teacher, along with her three children, were taken to hospital.", the underlined verb phrase must agree with the subject. Choose the option that best improves the verb phrase, or select No improvement if the sentence is already correct.

Introduction / Context:
This question tests subject verb agreement when the subject is followed by an additional phrase. The sentence mentions the teacher and then adds a modifying phrase along with her three children. Many learners mistakenly think that the presence of three children makes the subject plural, but in reality the verb must agree with the main subject of the sentence, which is singular. Correcting the verb form is the focus of this sentence improvement item.

Given Data / Assumptions:

• Sentence: The teacher, along with her three children, were taken to hospital.
• The underlined part is were taken.
• Options: was taken, had taken, had being taken, No improvement.
• The phrase along with her three children is a parenthetical addition, not a second subject.

Concept / Approach:
When a singular subject is followed by a phrase starting with along with, together with, accompanied by, or similar expressions, the verb still agrees with the main subject and remains singular. Here the main subject is the teacher, which is singular. Therefore, the verb should also be singular, that is, was taken. The verb phrase had taken changes the meaning to the teacher acting as a doer rather than as someone receiving action, and had being taken is grammatically incorrect. Thus, the correct choice is was taken, which keeps the passive meaning and agrees in number with the subject.

Step-by-Step Solution:
Step 1: Identify the core subject of the sentence before the comma: The teacher. Step 2: Recognise that the phrase along with her three children is a modifier that adds extra information but does not function as part of a compound subject. Step 3: Determine the correct number of the subject. The teacher is singular, so the verb should also be singular. Step 4: Examine the original verb were taken, which is plural and therefore incorrect for a singular subject. Step 5: Select was taken as the correct singular passive form, so the sentence reads The teacher, along with her three children, was taken to hospital. Step 6: Check option B, had taken, which would mean the teacher had taken her children somewhere, reversing the intended meaning. Step 7: Check option C, had being taken, which is not a valid English verb form and should be rejected.

Verification / Alternative check:
A useful method is to temporarily remove the parenthetical phrase and read the sentence with only the core subject and verb: The teacher was taken to hospital. This is clearly correct. Adding the phrase back in as The teacher, along with her three children, was taken to hospital keeps the singular verb and still conveys that the children went with the teacher. By contrast, The teacher, along with her three children, were taken to hospital fails the subject verb agreement test, because were does not agree with the singular teacher.

Why Other Options Are Wrong:
Had taken changes the voice from passive to active and suggests that the teacher acted on something, which does not fit the original meaning. Had being taken is simply not grammatical and does not appear in standard English. No improvement would preserve the incorrect plural verb were taken.

Common Pitfalls:
A common error is to look only at the noun closest to the verb, in this case children, and let that drive the choice of a plural verb. To avoid this mistake, always identify the main subject before any commas or interrupting phrases and make the verb agree with that subject. Phrases starting with along with, together with, as well as, and similar expressions do not change the number of the subject in formal English grammar.

Final Answer:
The correct improvement is was taken, giving: The teacher, along with her three children, was taken to hospital.