The answer is who because is makes it makes the most sense
Clustering is an important prewriting technique much like brainstorming and allows the writer to: (D) generate ideas and see connections between them. The trick is to write down whatever words related to a specific word or phrase comes to a writer's head. It is then key to draw associations between words to determine topic of an essay.
#1 is either D or A bit I’m pretty sure D (sorry I know that’s not super helpful)
#2 is C and #3 Is B
The answer is Percy Bysshe Shelley