I am sure Mike will lend you some money. I ___ if he refused ?

The question involves conditional reasoning, specifically relating to expectations and hypothetical situations. The phrase "I am sure Mike will lend you some money" indicates a belief about a future action. However, the clause "if he refused" introduces a hypothetical scenario that contrasts with the expectation presented earlier.

The correct choice, D) "would be surprised," fits this scenario perfectly. It suggests that if Mike were to refuse, the speaker would experience surprise based on the assumption that Mike will lend the money. This construction uses the second conditional, which is appropriate for discussing unreal or unlikely situations.

Option A ("will be surprised") suggests certainty about a future reaction, which does not align well with the hypothetical nature of the refusal. Option B ("am surprised") implies a current state of feeling, which doesn’t suit the future conditional nature of the statement. Lastly, Option C ("would have been surprised") indicates a past reaction to a past event, which is not relevant here. Thus, option D is the only one that presents a proper future conditional alignment, indicating the surprise that would follow a situation contrary to the speaker's expectations.