What is different between has and have

Pls, i really need on this question?

Which sentence best states a theme of gilman's "the yellow wallpaper"? a. women in the 19th century often played a lesser role in marriage. b. when a person is unwell, rest is the best medicine. c. a husband does not believe that his wife is sick, which leads to disastrous consequences. d. the narrator does not like the yellow wallpaper in her bedroom and becomes mentally disturbed.

Which would best develop a well-organized and logical research paper? a. narrow goals b. a variety of sources c. good research results d. a strong topic