Mr. Smith became very ______ when it was suggested that he had made a mistake.

【正确答案】 D

【答案解析】 形容词词义辨析。ingenious“有独创性的，机灵的”；empirical“经验主义的”；objective“客观的”；indignant，根据句意只有indignant“愤愤不平的”符合语境，故答案为D。