问题
______ 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
B: That it was in the 1980's
C: It was the 1980's
D: It was in the 1980's
正确答案是：
