Answer:
C. Homework improves learning by reinforcing ideas
Explanation:
The passage is basically concluding that, despite how annoying homework actually is, it has its benefits. It says it helps students practice the concepts they learned in school, and helps them better understand strong and weak points.
it doesnt mention this for the teacher in anyway, so we can rule this out. It also doesn't mention the opinion of parents, so we can rule that out as well.
It doesn't mention D either, so C should be our answer
