Solve the Formula for the Indicated Letter $c ^ { 2 } + d ^ { 2 } + f ^ { 2 } = g ^ { 2 }$

Multiple Choice

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

A) $c = g ^ { 2 } - d ^ { 2 } - f ^ { 2 }$
B) $c = - g + d + f$
C) $c = g - d - f$
D) $c = \sqrt { g ^ { 2 } - d ^ { 2 } - f ^ { 2 } }$