Nonfiction is considered a type of literature because it

There are two major differences between fiction and nonfiction. First, nonfiction writers must stick to things that really happened; writers of fiction can make up anything they wish. Second, fiction depends on a plot; nonfiction writers are much freer to bounce around in space and time to make their points.

So your answer is Nonfiction is considered a type of literature because it bases its overall plot on actual historical events.

can i see the painting?

the answer is a)   a sentence of death costs the state "almost three times as much as a sentence of life in prison" (delon 147)