Keilantra's math teacher plots student grades on their weekly quizzes against the number of hours they say they study on the pair of coordinate axes and then draws the line of best fit. What does the slope of the line represent?

A. The change in expected quiz score for every additional one hour students spend on their homework.
B. A prediction of a student's quiz score if they spent 1 hour on their homework.
C. The change in a student's actual quiz score for every additional one hour that student spent on their homework.
D. A student's expected quiz score if they spent no time on their homework.