In the following error spotting sentence, identify the part that contains a grammatical error: "The audience are (A) humbly requested to be (B) seated in their seats. (C) No error (D)".

Introduction / Context:
Error spotting questions in English grammar aim to test a learner awareness of subject verb agreement, usage of collective nouns, redundancy, and standard formal expressions. In this sentence, the phrase "The audience are humbly requested to be seated in their seats." is divided into parts labelled A, B, C, and D. The learner must determine which part contains an error. This type of sentence is very similar to announcements made in public places, so mastering the correct form is also useful beyond the examination hall.

Given Data / Assumptions:
- The sentence is split as follows: (A) The audience are, (B) humbly requested to be, (C) seated in their seats., (D) No error. - The sentence is intended to be formal and grammatically correct. - "Audience" is used as a collective noun. - Only one part contains a clear grammatical error.

Concept / Approach:
The key concept here is subject verb agreement with collective nouns. In standard formal British and Indian English, collective nouns such as "audience", "team", or "committee" can sometimes take plural verbs when the group is considered as individuals. However, in formal announcements where the group is treated as a single body, the singular verb is preferred. The phrase "The audience are humbly requested" sounds less natural than "The audience is humbly requested" in such context. There is also some redundancy in "seated in their seats", but competitive exam patterns usually focus on the obvious verb agreement issue in part A rather than on stylistic repetition.

Step-by-Step Solution:
Step 1: Identify the subject of the sentence, which is "The audience". It refers to a group of people seen as one unit that is being addressed. Step 2: Look at the verb form in part A, "are". If we treat the audience as a single body, the correct linking verb with a singular collective noun is "is". Step 3: The rest of the sentence, "humbly requested to be seated in their seats", is a standard formal passive structure used in announcements and does not contain a strict grammatical error, although stylistically "in their seats" is redundant. Step 4: Since the main grammatical issue lies in part A, where "are" should be replaced by "is", that part is marked as the error. Step 5: Therefore, option a, corresponding to part A, is the correct choice.

Verification / Alternative check:
To verify, rewrite the sentence with the corrected verb and read it aloud: "The audience is humbly requested to be seated in their seats." This sounds like a typical announcement made before a performance. If we keep "are", the sentence sounds slightly awkward in formal English, as if stressing the individuals rather than the group. Since the question style in such exams normally expects the singular verb with "audience" in announcements, this confirms that the error is in part A. No other part contains a definite rule based grammatical mistake.

Why Other Options Are Wrong:
Option b, part B "humbly requested to be", is a standard polite passive wording in formal contexts and is grammatically acceptable. Option c, part C "seated in their seats", is redundant in style but not grammatically incorrect, so it is usually not the focus of such error spotting questions. Option d, part D "No error", is wrong because we have already identified a subject verb agreement issue in part A.

Common Pitfalls:
Learners sometimes get confused because they have also seen sentences like "The audience were clapping loudly", where the group is viewed as separate individuals, and a plural verb is acceptable. In a formal request or announcement, however, examiners prefer the singular treatment. Another common pitfall is over focusing on stylistic redundancy, for example objecting to "seated in their seats", when the test pattern typically targets clear grammatical disagreements rather than minor repetition.

Final Answer:
The part containing the grammatical error is in segment A, so the correct choice is A.