I think this problem is that one. A. easyB. easierC. easier thanD. the easiest

问题补充：

I think this problem is that one.

A. easy

B. easier

C. easier than

D. the easiest

答案：

A. easy

B. easier

(答案→)C. easier than

D. the easiest

解析：这个问题和那个问题相比较，要用比较级形式，比……，用than。所以选C。