In the story, Jeanne imagines that hatred looks like a "dark, amorphous cloud" that will descend and enclose her family forever. This frightening imagery describes how Jeanne feels about her family's journey back west. Essentially, no one in Jeanne's Japanese American community is thrilled with the idea of returning west.

To facilitate her family's move, Jeanne's father purchases a car. In chapter 19, we are told that Jeanne's father has to make three trips to finish relocating the entire family from Owens Valley to Long Beach.

Certainly, the relocation process is an arduous one. However, Jeanne and her family most fear the animosity they will face in the communities they once belonged to. To Jeanne, hatred is a nebulous, malignant force that has the power to destroy her family.

In fact, Jeanne worries that three years of war propaganda, "atrocity movies, hate slogans, and fright-mask posters" has turned their former neighbors against them. Additionally, Jeanne fears that organizations like No Japs Incorporated and the Pacific Coast Japanese Problem League have fomented continued distrust of Japanese Americans. So, we can see that Jeanne is most concerned about the hatred that will greet her family on the west coast.

You can find the answer to this question in Chapter 19 -- the one entitled "Reentry."  This chapter describes what happens as the Wakatsuki family is allowed to leave the camp at Manzanar.

Papa buys a car and the family heads back to Los Angeles.  As they do that, they start to worry about what kind of a reception they will get from all the white people.  They worry that they will be hated.  Jeanne imagines that the hate would look like a "dark, amorphous cloud" that would come down on them.

So the best answer of these would be B -- a dark cloud.