The answer you seek is “the practice of having two or more husbands”
A is an example of false cause and effect
There is no concrete fact that diet soda can cause definite cancer prevention.
"Breaking with tradition" is a major theme of modernist literature. Therefore, the correct answer is the second one -- it emphasizes the changing values of the time.
In this case, the changing values involve women's appearance. For centuries, women had long hair. A woman with very short hair was never seen. In the story, though, short hair is becoming the fashion.
