Find the Domain and Range of the Function $f ( x ) = x ^ { 2 } - 18 x + 84$

Multiple Choice

Find the domain and range of the function.
$f ( x ) = x ^ { 2 } - 18 x + 84$

A) $\text { Domain: } [ 3 , \infty ) \text {; Range: } ( - \infty , 9 ]$
B) $\text { Domain: } ( - \infty , \infty ) \text {; Range: } [ 3 , \infty )$
C) $\text { Domain: } [ 3 , \infty ) \text {; Range: } ( - \infty , 0 ]$
D) $\text { Domain: } ( - \infty , \infty ) \text {; Range: } [ 9 , \infty )$