单项选择题

Questions 17 to 20 are based on the following passage. At the end of the passage ,you will be given 20 seconds to answer the questions.
Now listen to the passage.

At first, why did more women get jobs

A.Their income was needed to support the family.
B.Their parents moved in with them.
C.They were bored with housework.
D.They needed more money because they had more children.