The Exposure Coefficient in the Regression P = a $\frac { \operatorname { Cov } ( P , S ) } { \operatorname { VAR } ( S ) }$

The exposure coefficient in the regression P = a + b × S + e is given by

A) b = $\frac { \operatorname { Cov } ( P , S ) } { \operatorname { VAR } ( S ) }$
B) P = a + b × S + e
C) b = $\frac { \operatorname { Cov } ( P , S ) } { \operatorname { VAR } ( P ) }$
D) none of the options