Questions 15 to 18 are based on the conversation you have just heard.

Which of the following doesn’t the woman mention as the way to get information

A．the longer one sleeps, the less sound sleep he gets
B．the more sleep one gets, the more likely a stroke occurs
C．many people stick to about eight hours of sleep to stay fine
D．many people who sleep six hours a night still feel energetic in the day

A．didn’t think he was ready to propose to her
B．suspected that husband and wife would often quarrel
C．didn’t think eight years was long enough
D．was waiting for his mother-in-law’s approval