Solve $d = \frac { 4 c b } { b + c }$

Multiple Choice

Solve $d = \frac { 4 c b } { b + c }$ for b.

A) $b = \frac { c d } { 4 c - 1 }$
B) $b = \frac { 1 } { 4 }$
C) $b = \frac { d ( b + c ) } { 4 c }$
D) $b = \frac { c d } { 4 c - d }$