Solve for the Specified Variable $A = 3 \pi a ^ { 2 } ;$

Multiple Choice

Solve for the specified variable. Assume that all other variables are nonzero
- $A = 3 \pi a ^ { 2 } ;$ for $a$

A) $a = \sqrt { 3 \pi \mathrm { A } }$
B) $a = \frac { \pm \sqrt { 3 \pi \mathrm { A } } } { 3 \pi }$
C) $a = \frac { \pm \sqrt { \mathrm { A } \pi } } { 3 }$
D) $a = \frac { \pm A \sqrt { 3 \pi } } { 3 \pi }$