It/ not easy/ remain/ tranquil/ events/ suddenly/...

Câu hỏi: It/ not easy/ remain/ tranquil/ events/ suddenly/ change/ life.  

A It is not easy remain tranquil when events suddenly change life.

B It is not easy to remain tranquil when events suddenly change your life.

C It is not easy remaining tranquil when events suddenly change your life. 

D It is not easy to remain tranquil if events suddenly change life.