How does the brainstorming method of free writing in writing a research paper?

 In brainstorming or freewriting you jot down words, phrases, and sentences that pop into your mind in no special order (not organized or logically arranged), but they are all associated with a particular topic (in this case, the subject of the research paper) . Therefore I would choose (B). Answer (C) sounds like a possibility, except for the part about a timed session. I suppose you could limit your brainstorming session to a specific time but I don 't think timing is an inherent feature of brainstorming. (B) makes sense to me because the ideas you jot down are all connected to the topic. After you have the brainstorming list you can begin to make connections between the items you wrote down. When you jotted them down they were not yet connected logically to each other, they were only connected individually to the main topic. So this method would only help you if you subsequently brought the items together in some coherent way.

It helps you in a way of opening your imagination 

Identify the theme of the story in your sentence