that saw the trade between the two countries reach its highest point.　　A. During the 1980

问题补充：

that saw the trade between the two countries reach its highest point.

A. During the 1980’s

B. That it was in the 1980’s

C. It was the 1980’s

D. It was in the 1980’s

答案：

A. During the 1980’s

B. That it was in the 1980’s

(答案→)C. It was the 1980’s

D. It was in the 1980’s

解析：本题测试强调句型。基本结构：It is+强调部分+that+句子其他成分。根据上下文，本句是强调句子的主语“the 1980’s”，故答案为C。