William Faulkner was the foremost American _____ writer of the 20th century.

A．we shouldn't blame a person if he fails to act in emergencies
B．a person must feel guilty if he fails to help
C．people should be responsible for themselves in emergencies
D．when you are in trouble, people will help you anyway

A．to explain why people fail to act in emergencies
B．to explain when people will act in emergencies
C．to explain what people will do in emergencies
D．to explain how people feel in emergencies