The Denominator of the Pearson R Is $C P _ { X Y }$

Multiple Choice

The denominator of the Pearson r is.

A) $C P _ { X Y }$
B) $\sum ( X - \bar { X } ) ( Y - \bar { Y } )$
C) $\left( S S _ { X } \right) \left( S S _ { Y } \right)$
D) $\sqrt { \left( S S _ { X } \right) \left( S S _ { Y } \right) }$