Concept:An exclamatory sentence expresses strong emotion like surprise, joy, or anger and always ends with an exclamation mark (!).Explanation:Look at each sentence. Option A: "What a piece of work is man!" ends with an exclamation mark and conveys admiration. This is an exclamatory sentence. Option B: "What do you know about ancient India?" is a question, so it is interrogative. Option C: "Which is your favourite book?" is also a question. Option D: "His cruelty knew no bounds." makes a statement and ends with a full stop; it is declarative. Only option A fits the definition. Exclamatory sentences often begin with "What" or "How" to show strong feeling.Answer:A. What a piece of work is man!