Find the Slope of a Line That Has the Given $3 x + y = - 8$

Multiple Choice

Find the slope of a line that has the given relationship to the given line. If the slope is undefined, state this.
-Perpendicular to $3 x + y = - 8$

A) $- \frac { 1 } { 3 }$
B) 3
C) $- 3$
D) $\frac { 1 } { 3 }$