what are key course concepts? are they just basic terms of vocab you would have learned in class? (pls don't give a copy/paste definition from google)

Key course concepts represent the big ideas in a chapter, section, or course.

Explanation:

Let's break it down into definitions.

Key → of paramount or crucial importance

Course → a series of lectures or lessons in a particular subject

Concepts → an abstract idea; a general notion

"A general notion" in "a series of lectures or lessons" of "crucial importance". If we reword it, we understand that "key course concepts" means the main takeaways or notions that you can learn from a section of your textbook or class.

it is the background information on the characters and setting explained at the beginning of the story. the exposition will often have information about events that happened before the story began. the exposition is often the very first part of the plot.

i think it may be b, i'm not exactly too sure on this. but b seems to make more sense.