A、Infection. B、Cavity. C、Caries. D、None of the above. A由女士的回答“Your tooth is infected”可知，男士的牙齿受到感染了，所以牙痛是由于感染所致。故选A。

W: Hello, Mr. Wang. How are you doing?
M: Mm… I’m well, but I have come here for something.
W: Oh, really? Have you been having any problems?
M: I’ve been having a toothache.
W: Can you describe the pain for me?
M: It’ s quite a dull pain, and my face is swollen.
W: Does it hurt just during the day or at night as well?
M: It hurts all the time…
W: ls the tooth sensitive to hot or cold?
M: Yes, it hurts when I drink anything hot.
W: Your tooth is infected, and there might be an abscess under it. I will give you an antibiotic to reduce the infection. If the swelling doesn’ t go down,I’m afraid I will have to lance it or perhaps root canal.
Q1: What is the woman’ s occupation?
Q2: What is NOT true about the man’ s toothache?
Q3: What might be the cause of the toothache?