In the following sentence, one part may have an error. Identify the part that contains an error, if any, in the sentence: The students refused (A) / to accept responsibility (B) / for their acts (C) / No Error (D).

Introduction / Context:
This is another classic error spotting question. The sentence is divided into parts, and the aspirant must decide whether any part violates standard English grammar or usage. The focus here is on verbs, infinitives, and noun phrases describing what the students refused to do. Recognising correct structures is just as important as finding mistakes in competitive examinations.

Given Data / Assumptions:
The sentence is presented as The students refused (A) / to accept responsibility (B) / for their acts (C) / No Error (D). The question asks which part, if any, contains an error. We assume neutral formal English with no colloquial distortions. The context suggests a group of students who do not wish to admit their wrongdoing.

Concept / Approach:
First we note that refused to accept is a correct verb plus infinitive structure. The noun phrase responsibility for their acts is also normal in English and expresses the idea of owning the consequences of one behaviour. The plural subject the students agrees logically with the plural pronoun their. There are no tense issues, since refused correctly indicates a completed past action. Therefore, all parts of the sentence are grammatically sound and idiomatic.

Step-by-Step Solution:
Step 1: Identify the main verb phrase: refused to accept, which is a standard combination indicating a decision not to accept something. Step 2: Check that the infinitive to accept is correctly formed and follows refused without any missing words. Step 3: Examine the object phrase responsibility for their acts, which uses the correct preposition for to connect responsibility and acts. Step 4: Confirm that the subject the students agrees with the plural pronoun their and that the sentence expresses a clear and complete idea. Step 5: Conclude that none of the first three parts contain errors, so the only correct response is the No Error option.

Verification / Alternative check:
We can restate the sentence as The students refused to accept responsibility for what they had done, which is clearly correct and natural English. Any attempt to change the structure, such as The students refused accepting responsibility or refused for accept, would sound incorrect or awkward. This confirms that the original construction refused to accept responsibility for their acts is well formed and does not need any correction.

Why Other Options Are Wrong:
Option A is correct because refused is the proper past tense form of refuse and is suitable for a plural subject.
Option B is correct because to accept is the correct infinitive and follows refused directly as required.
Option C is correct because responsibility for their acts uses the right preposition for to indicate what the responsibility concerns and the pronoun their correctly refers back to the students.
Thus, since there is no grammatical or usage error in any of the first three parts, Option D, No Error, must be chosen.

Common Pitfalls:
Students sometimes over analyse sentences in this type of question and start doubting perfectly normal patterns like refuse to accept or responsibility for something. Anxiety about missing a hidden trick can lead them to mark an error where none exists. It is important to trust common collocations and to recognise that exam setters intentionally include fully correct sentences to test a candidate confidence and familiarity with standard English structures.

Final Answer:
The sentence is correct as it stands, so the correct option is D (No Error).