In this English sentence improvement question based on vocabulary and collocation, you must correct the clause "Teachers are exemplary to the virtues of middle class" by choosing the option that best expresses the idea that teachers represent or illustrate the virtues of the middle class.

Introduction / Context:
This question focuses on the correct verb choice and collocation in the sentence "Teachers are exemplary to the virtues of middle class." It tests whether you know how to use the verb "exemplify" to express the idea that someone or something is a typical example of a quality or group. Such questions are common in competitive exams because they reveal how naturally a candidate uses higher level vocabulary.

Given Data / Assumptions:

• Incorrect sentence: Teachers are exemplary to the virtues of middle class.
• The intended meaning is that teachers represent or embody virtues typical of the middle class.
• The underlined part is "are exemplary to".
• We must choose the single word or phrase that correctly expresses this idea.

Concept / Approach:
The adjective "exemplary" means "serving as a desirable model" or "very good", but the phrase "are exemplary to the virtues" is not idiomatic English. The verb "exemplify" means "to be a typical example of" or "to illustrate". Therefore, "Teachers exemplify the virtues of the middle class" is the correct and natural way to express that teachers are good representatives of those virtues. The exam is testing whether you select the right verb instead of trying to misuse the adjective.

Step-by-Step Solution:
Identify the idea: teachers represent or show clearly the virtues of the middle class.Recognise that we need a verb that means "to be an example of".Recall the verb "exemplify", which exactly means "to illustrate by example" or "to be a typical example of".Form the correct sentence: "Teachers exemplify the virtues of the middle class."Confirm that this construction is standard and idiomatic in formal English.

Verification / Alternative check:
Read the improved sentence: "Teachers exemplify the virtues of the middle class." It is concise, grammatically correct, and uses "exemplify" precisely. This is the sort of sentence you might see in an essay or article praising the role of teachers in society, confirming that the chosen verb is appropriate.

Why Other Options Are Wrong:
Option B: "are examples to" would give "Teachers are examples to the virtues of middle class", which is not a correct structure because you cannot be "examples to virtues". You can be examples to people, but not to abstract qualities. Option C: "exemplificate" is not a standard English word and is therefore incorrect. Option D: "No improvement" is wrong because "are exemplary to" is not idiomatic and sounds awkward.

Common Pitfalls:
Students often think that if they know an adjective like "exemplary", they can simply add linking verbs like "are" and a preposition to build a sentence. However, English has specific patterns and some meanings are more naturally expressed with verbs like "exemplify". It is important to learn not just individual words but also the common combinations and sentence patterns they appear in.

Final Answer:
The correct improvement is to use the verb exemplify, giving the sentence "Teachers exemplify the virtues of the middle class."