Which of the following italicized parts is an appositive clause？A．They were surprised at t

Which of the following italicized parts is an appositive clause？

A．They were surprised at the fact that ocean ships can sail up the Great Lakes.

B．I have read all the books that you gave me.

C．He told me that he would go to the college the next year.

D．The truth is that I didn"t finish my term essay.

请帮忙给出正确答案和分析，谢谢！