Liz's math test included a survey question asking how many hours students spent studying for the test. The scatterplot and regression line below show the relationship between how many hours students spent studying and their score on the test.
The fitted line has a slope of 15.
What is the best interpretation of this slope?

A
The model predicts that students who scored 0 studied for an average of 15 hours.
(Choice B)
B
The model predicts that students who didn't study at all will have an average score of 15 points.

(Choice C)
C
The model predicts that the score will increase 15 points for each additional hour of study time.

(Choice D)
D
The model predicts that the study time will increase 15 hours for each additional point scored.