I am sure it was by mistake that your closes...

Câu hỏi: I am sure it was by mistake that your closest friend took your English book.

A. Your closest friend must have taken your English book by mistake. 

B. I am sure your closest friend didn’t take your English book deliberately. 

C. It is a mistake that your closest friend took your English book. 

D. It is certain your closest friend didn’t take your English book on purpose.