There is no simple answer, is often the case in science. A. asB. that C. when D. where

There is no simple answer, is often the case in science.
A. as
B. that
C. when
D. where

(答案→)A. asB. that C. when D. where解析：此处as引导定语从句指代整个主句内容，含有“正如”之意，定语从句部分译为“在科学上这是常有的事”。【考点定位】考查定语从句

这个答案应该是对的