选择题：13. — Have you graduated from collage?— Yes , ____

题目内容：
13. — Have you graduated from collage?— Yes , ________.(本题2.0分)
A、 I studied French for two years.
B、 I have been studying French.
C、 I have studied French for two years.
D、 I had studied French for two years.
参考答案：