Answer:
I would say D, but B could be an option.
Explanation:
The main purpose of the post-reading phase is to check for accurate comprehension of the text.
A: Helping you organize your notes doesn't really relate to post-reading evaluation. I mean, it could, but it's unlikely.
B: More prior knowledge before a test or discussion.
C: How would this make it easier to learn new words?
D: By determining your own opinion of a text you can have a clear sight on what the article is saying.
Hope this helped :/