Which of these sentences is correct ?

A．She wondered what’s wrong with her dog.

B．I am not sure what does he do for a living.

C．Nobody knows how he repaired his broken bike this morning.

D．He asked if that it would rain the following day.

脉冲强光是一组复合光，对皮肤具有多重治疗作用，常用来治疗（）。