Passage 1

Which of the following statement is true a. Dr. Sellers invented the word face blindness. b. Brain scans show that a certain part of the brain of person with face blindness is inactive at all compared with that of a normal person. c. A certain part of the brain of a normal person will react differently to the faces of two different persons. d. Face blindness is accompanied by some symptoms like color blindness.

患者一年来自觉左下后牙咀嚼不适求治，检查发现左下第二前磨面中央处见黑点，探无痛，右下同名面也见相同黑点，叩(+)松(-)，未查见龋坏，出现该症状最有可能的原因是()

A．隐裂

B．畸形中央尖

C．血源性感染

D．逆行性牙髓炎

E．原因不明的牙髓坏死