A regression equation was constructed relating the time spent studying for an exam (X) and the score received on the first exam (Y) for 25 students in a calculus course. The y-intercept was found to be 95 while the slope was found to be -0.8. In addition, the coefficient of determination was calculated to be 60.0%. What is the correlation coefficient between X and Y in this problem (rounded to 2 decimal places)?
A. -0.36
B. 0.77
C. -0.77
D. 0.60