A regression analysis between sales (in thousands of dollars) and advertising (in hundreds of dollars) resulted in the following least squares line: $\hat{y} = 75 + 6x$. This implies that if advertising is 800 dollars, then the predicted amount of sales (in dollars) is:
A. 487,500 dollars
B. 12,300 dollars
C. 123,000 dollars
D. 4,875 dollars

Given the least squares regression line $\hat{y} = -2.48 + 1.63x$, and a coefficient of determination of 0.81, the coefficient of correlation is:
A. 0.90
B. -0.90
C. -0.85
D. 0.85