M: The taxi driver must have been speeding.
W: Well, not really. He crashed into the tree because he was trying not to hit a box that had fallen off the truck ahead of him.
Question: What do we learn about the taxi driver

A. He turned suddenly and ran into a tree.
B. He was hit by a fallen box from a truck.
C. He drove too fast and crashed into a truck.
D. He was trying to overtake the truck ahead of him.

女性，46岁。右上后牙进食时有时产生剧烈疼痛3个月余。无自发痛。口腔检查：右上5远中邻面深龋洞，有大量软垢，牙石堆积，探诊浅探不痛，深探剧痛。去除腐质可见穿髓孔，温度刺激试验敏感。最佳治疗方案是（）

A.塑化术

B.直接盖髓术

C.牙髓切断术

D.根管治疗术

E.开髓引流