The literary device used on the title of the poem "War is Kind" is the following:
A. Irony
Irony is the expression of one's meaning by using language that normally signifies the opposite, typically for humorous or emphatic effect. This idea of expressing the opposite of what is actually being said/wrote is present on the title: in this case, by the use of the word "Kind".
Mexican America Cesar Chavez (1927-1993) was a prominent Union leader and labor organizer. Hardened by his early experience as a manual laborer, Chavez founded the national Farm workers Association in 1962. His union joined with the agricultural workers organizing committee and its first strike against grape growers in California, and the two organizations later merged to become the United farmworkers. Stressing Nonviolent methods, Chavez drew attention for his causes via boycotts, marches in hunger strikes. Despite conflict with the Teamsters Union and legal barriers, he was able to secure raises and improveConditions for farmworkers in California, Texas, Arizona and Florida.
A situation in when you would be incredulous is when something happens that you can't believe or unwilling to believe.
"Longing" is another word for: (C) NOSTALGIA
When you are nostalgic about something, you long for something or someone in the past. For example, a person who migrates to another country might become nostalgic for the foods and culture of his own country as he tries to settle in.