The Appropriate Range for the Coefficient of Correlation (R) Is $\le$

Multiple Choice

The appropriate range for the coefficient of correlation (r) is

A) 0 $\le$ r $\le$ 1.
B) -% $\le$ r $\le$ +%.
C) -1 $\le$ r $\le$ 1.
D) -1 $\le$ r $\le$ +%.