Answer:
B. compare and contrast.
Step-by-step explanation:
An essay that employs the structure of "compare and contrast" is one that picks two topics that are connected in a meaningful way and talks about both of them at the same time. This essay is likely to employ phrases such as "during the same period." This is because the phrase indicates that the essay talks about two topics that are connected because of the time period in which they happened, but that are otherwise distinct.