Solve the Equation for the Indicated Variable $r m = t ^ { 2 } - m t$

Multiple Choice

Solve the equation for the indicated variable. Assume no denominator is 0.
- $r m = t ^ { 2 } - m t$ , for $t$

A) $t = \frac { m \pm \sqrt { m ^ { 2 } - 4 m r } } { 4 }$
B) $t = \frac { m \pm \sqrt { m ^ { 2 } + 4 m r } } { 2 m }$
C) $t = m \pm \sqrt { m ^ { 2 } + 4 r m }$
D) $t = \sqrt { m r - m }$