Step 1: Understanding the Concept
The question asks for the function of the sentence, which is a statement made to another person about their work.
Step 2: Analyzing the Sentence's Content and Tone
The sentence states a positive fact ("You have written a poem") and includes a strong positive adjective ("wonderful"). Praising someone's work or qualities is an act of appreciation or giving a compliment. The tone is positive and admiring.
Step 3: Evaluating the Options
(A) suggesting: To propose an idea. The speaker is not suggesting anything; they are commenting on a finished action.
(B) appreciating: To recognize the full worth of; to show gratitude or admiration. By calling the poem "wonderful," the speaker is showing appreciation for the writer's skill. This is the correct function.
(C) commanding: To give an order. This is a declarative statement, not a command.
(D) complaining: To express dissatisfaction. The sentence expresses satisfaction and admiration, the opposite of a complaint.
Step 4: Final Answer
Giving a positive judgment on someone's creation using words like "wonderful" is an act of appreciation. Therefore, option (B) is correct.