Answer:
A. to generate as many ideas as possible to include in the writing
Step-by-step explanation:
when you identify the purpose of a piece of writing, it's important because after you identify it, you can generate any amount of ideas, such as what the author accomplished, who the author's audience is, etc. these are ideas that you can include in your own writing. for example, you could include them in an essay about that piece of writing.
when you cannot identify the purpose, it's much harder to understand that piece of writing, and you might get confused more easily with it.