In the regression equation Grade Total = 0.3 + 0.2Study time, what is the impact of study time on grade

For every one hour devoted to study, the grade total will decrease by 0.2 points

For every one hour devoted to study, the grade total will improve by 0.2 points.

For every one mark of grade total, study time devoted will improve by 2 hours

For every one hour devoted to study, the grade total will improve by 0.3 points