Solve for the Specified Variable $S=\frac{a}{1-r}$ For $r$ A) $r=\frac{S-a}{S}$ B) $r=S-a$ C) $r=\frac{a}{S}-1$ D) $r=\frac{a}{S}$

Multiple Choice

Solve for the specified variable.
- $S=\frac{a}{1-r}$ for $r$

A) $r=\frac{S-a}{S}$
B) $r=S-a$
C) $r=\frac{a}{S}-1$
D) $r=\frac{a}{S}$