Answer:
D. can reveal an interesting angle that may become your thesis.
Explanation:
This is the main way in which prewriting can help you narrow a topic. When you are in the stage of "prewriting," you need to think about all the different angles and possibilities that you could use in order to design your thesis and examine it. This is similar to the process of brainstorming. Depending on the angle that you chose, your thesis could vary in uniqueness, manageability, etc.