A, you always need a hook, thesis, and a little bit of backround info
The answer would be A. The rest of the sentence is in past tense, so that would also be.
D. Intelligent, because the third letter is t, which comes after S so can't be inside or inspection.
From my my experience this usually differs depending on the type of book it is, but I think the best choice is either A, to help the reader understand new concepts, or C., It allows the reader to focus on key ideas and information during the reading. I'd pick C though, since it's more in depth and makes more sense.
B. doesn't make that much sense unless the book is an argumentative or a persuasive book.
D. only applies to personal narratives. Nobody can understand a writer's personal experiences and attitudes otherwise.
Answer: A big tree
Explanation:
A nice elm tree with many outstretched branches