C) It is ironic that the young married women have so much, and yet feel quiet unhappy.
Irony is when the opposite of what is expected happens. The entire passage describes how easy life is for the young married women in Floral Heights and other prosperous areas of Zenith. One would expect the women to be happy that they want for nothing and only have to work for two hours a day. They can spend their days in leisure, enjoying the company of their friends. However, at the end it is revealed that they are actually unhappy. This is the opposite of what is expected and therefore, ironic.
D. The thesis. It's going be your statement that you're trying to prove.
I think the first one is the enwrapped one