—How did you miss your train？—（）.A.Well，I was caught in the traffic jam B.What’s your proposal C.Nev

—How did you miss your train？—（）.A.Well，I was caught in the traffic jam B.What’s your proposal C.Never mind

The correct answer is A. Well, I was caught in the traffic jam. This directly explains the reason for missing the train, which logically responds to the question "How did you miss your train?"

Option B ("What’s your proposal") is irrelevant as it asks a question rather than providing an explanation, while Option C ("Never mind") dismisses the question instead of answering it. The traffic jam scenario is a common and plausible reason for missing transportation, making A the natural choice in conversational English.