The main idea of the story is that ________.
选项：

A:Dorothy and Tim, as mother and son, overcame a misunderstanding and made up to each other at last;
B:Dorothy, the mother in the house, quarreled with her daughter-in-law and decided to leave and start over;
C:Dorothy was worried about her place in the house when her daughter-in-law began to stay at home full time;
D:thinking that she was redundant in the house, Dorothy decided to leave but her son and daughter-in-law convinced her that she was welcome and needed