David said that it was because of his strong interest in literature he chose the course.A

问题补充：

David said that it was because of his strong interest in literature he chose the course.

A. that

B. what

C. why

D. how

答案：

(答案→)A. that

B. what

C. why

D. how

解析：这个句子稍微复杂点。Said that 后面的是宾语从句。然后在这个从句里，有一个it is…that的强调句。整个宾语从句意思说：正是因为他对文学有浓厚的兴趣，他才选择了这个课程。