For Questions , Use the Following Narrative

For Questions , use the following narrative
Narrative: Study time and exam score
Suppose an algebra professor found that the correlation between study time (in hours) and exam score (out of 100) is +.80, and the regression line was found to be y = 20 + 4x.He arrived at this equation through years of collecting data on his students, most of whom reported studying anywhere from 0 to 20 hours for his exams.
-{Study time and exam score narrative} Suppose the professor later found out that his correlation was not +.80, but rather it was +.08.How does this change the predictions he can make about exam scores based on study time?

A) You have to take the results and divide them by 10, because .80/10 = .08.
B) It won't change the predictions because the regression line stays the same.
C) The predictions should no longer be used because they won't be very accurate.
D) Not enough information to tell.