Answer: B. subject by subject
Step-by-step explanation:
The subject by subject organizational format of comparing two topics works by writing paragraphs about the attributes of the various topics being described in different paragraphs.
For instance, Subject A attribute A will be on the first paragraph and Subject B attribute A will be on the second paragraph.
This will allow for a deeper evaluation of two topics because the characteristics will have to be expounded upon to make the paragraphs an appropriate length.