Question

When Sean spit on the floor of the library, it was clear that he was totally unaware of society’s mores.

Answer 1

is it a. charms
b. customs
c.hopes
d.feelings

Answer 2

You can guess by the context of the sentence. What makes the most sense? Society doesn't have hopes and feelings so C & D are immediately out.

That leaves you with A and B. Society can perhaps have charms, but it's not likely. Thus "customs" makes the most sense here.

Answer 3

Agree with customs

Answer 4

The answer is (b), customs.