Solve for the Indicated Variable $$P = \frac { A } { ( 1 + r ) ^ { 2 } } , \text { for } r$$

Solve for the indicated variable. Assume the variable you are solving for must be greater than 0.
- $$P = \frac { A } { ( 1 + r ) ^ { 2 } } , \text { for } r$$

A) $$r = \frac { P + \sqrt { P ^ { 2 } + A P } } { 2 }$$
B) $$r = \frac { - P + \sqrt { P ^ { 2 } - A P } } { P }$$
C) $$r = \frac { - \mathrm { P } + \sqrt { \mathrm { AP } } } { \mathrm { P } }$$
D) $$r = \frac { P + \sqrt { \mathrm { AP } } } { 2 \mathrm { P } }$$