Topic: Sentence (বাক্য),

Best Answer Explained in Below-:

The question "A lady asked him if he knew the time for the next train to Oxford" involves extracting information about a specific inquiry made by the lady. The correct answer is D: "What did a lady ask him?" because it directly aligns with the content of the original statement by seeking to clarify the specific question posed by the lady.

Option A, "Who asked him a question?" focuses on identifying the speaker but does not delve into the content of the question itself, making it less relevant. Option B, "Why did I know the time for the next train to Oxford?" is a misinterpretation that introduces unnecessary speculation regarding knowledge rather than addressing the lady's inquiry. Lastly, Option C, "A lady asked him a question, didn't she?" while true, simply confirms the action without asking for the specifics of the question.

In conclusion, Option D effectively captures the essence of the lady’s inquiry by seeking explicit details about her question, which ultimately makes it the most appropriate and relevant choice.