Solve the Problem $a$ Is $b$ Plus Nine, And $c$ Is the Square Of

Multiple Choice

Solve the problem.
-If $a$ is $b$ plus nine, and $c$ is the square of $a$ , write $c$ as a function of $b$ .

A) $c ( b ) = ( b + 9 ) ^ { 2 }$
B) $c ( b ) = b + 81$
C) $c ( b ) = 2 b + 18$
D) $c ( b ) = b ^ { 2 } + 81$