Solve the Formula for the Indicated Variable $I = \frac { n E } { n r + R }$

Multiple Choice

Solve the formula for the indicated variable.
- $I = \frac { n E } { n r + R }$ , for $n$

A) $n = \frac { R } { E - I r }$
B) $n = \operatorname { IR } ( \operatorname { Ir } - \mathrm { E } )$
C) $n = \frac { I R } { E - I r }$
D) $n = \frac { I R } { I r + E }$