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.

女，35岁。变色。患牙无自发痛和冷热刺激痛史。2年前，患牙曾有外伤史，未做过治疗。查：牙冠完整，呈暗黄色，无光泽，叩痛（-），温度及电活力测无反应，X线片未见根尖周明显异常。患牙应诊断为（）

A．牙髓钙变

B．牙髓坏死

C．牙髓纤维性变

D．牙内吸收

E．牙髓充血