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

Multiple Choice

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

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