Factor the Trinomial Completely $6 a ^ { 2 } - 36 a - 162$

Multiple Choice

Factor the trinomial completely. $6 a ^ { 2 } - 36 a - 162$

A) $( 6 a - 54 ) ( a + 3 )$
B) $6 ( a - 9 ) ( a + 3 )$
C) $6 ( a + 9 ) ( a - 3 )$
D) $( 6 a - 18 ) ( a + 9 )$
E) not factorable