Compute the Derivative Function $f ^ { \prime } ( x )$

Multiple Choice

Compute the derivative function $f ^ { \prime } ( x )$ algebraically.
$f ( x ) = - 5 x + 7$

A) $f ^ { \prime } ( x ) = - 5$
B) $f ^ { \prime } ( x ) = 0$
C) $f ^ { \prime } ( x ) = x$
D) $f ^ { \prime } ( x ) = 2$
E) $f ^ { \prime } ( x ) = - 5 x$