Answer: D. What is the author's purpose in writing this text?
Explanation: Reading is an excellent way to improve one's comprehension abilities. The best question to ask while reading a text is to figure out why the author wrote it in the first place. Option A proposes a method for remembering a text that is not the purpose of reading.
Option B and C are likewise inappropriate because they focus solely on reading the text rather than analyzing and improving one's comprehension abilities. To increase one's reading skills, one should try to comprehend the author's motivation for writing the material while reading.