Factor the Trinomial Completely $x ^ { 2 } - 8 x - 240$

Multiple Choice

Factor the trinomial completely. $x ^ { 2 } - 8 x - 240$

A) $( x - 20 ) ( x - 12 )$
B) $( x - 20 ) ( x + 12 )$
C) $( x + 20 ) ( x - 12 )$
D) $( x + 20 ) ( x + 12 )$
E) not factorable