Peter was seen crying when he came out of the office. We can deduce that he must have been punished.

【正确答案】 D

【答案解析】解析：题干：彼得哭着从办公室出来了。我们可以推测出他肯定受罚了。由从句that后面的he must have been punished可知前面的deduce的意思是“推测，推断”。confer商讨；refer提及，参考；infer推断，推理。故答案为D。