Solve the Formula for the Given Letter $F = \frac { a + b } { 2 } h \text { for } a$

Multiple Choice

Solve the formula for the given letter. $F = \frac { a + b } { 2 } h \text { for } a$

A) $a = \frac { 2 F - h b } { h }$
B) $a = \frac { 2 F - h b } { b }$
C) $a = \frac { 2 F + h b } { b }$
D) $a = \frac { 2 F + h b } { h }$
E) $a = 2 F - b$