Solve the Formula for the Indicated Letter $a S ^ { 2 } + b S = c$

Multiple Choice

Solve the formula for the indicated letter. Assume that all variables represent nonnegative numbers.
- $a S ^ { 2 } + b S = c$ , for $S$

A) $S = \frac { - b + b ^ { 2 } - 4 a c } { 2 a }$
B) $S = \frac { - b + b ^ { 2 } + 4 a c } { 2 a }$
C) $S = \frac { - b + \sqrt { b ^ { 2 } + 4 a c } } { 2 a }$
D) $S = \frac { - b + \sqrt { b ^ { 2 } - 4 a c } } { 2 a }$