单项选择题

Questions 18 ~ 21 are based on the following interview between a reporter and Mrs. Smith on her exchanging roles with her husband. Why did Mrs. Smith change her roles with her husband

A.Because she has been bored about the housework.
B.Because she has got a job at a salary higher than her husband’s.
C.Because she wants to communicate with the people.
D.Because she finds it interesting to work outside.