The correct answer is subject-by-subject organizational method. An essay organized in a subject-by-subject pattern first will present all the arguments related to A, and then will compare and/or contrast them to all arguments related to B. The arguments discussed for A should be presented in the same order for B. The organization of the paragraphs would be as follows:
Introduction
Paragraph topic A:
- Point 1 about A
- Point 2 about A etc.
Paragraph topic B:
- Point 1 about B (with discussion about connections to A)
- Point 2 about B (with discussion about connections to A) etc.
Conclusion