Mentally Factor the Trinomial $a ^ { 2 } + a - 56$

Multiple Choice

Mentally factor the trinomial $a ^ { 2 } + a - 56$

A) $( a - 7 ) ( a + 8 )$
B) $( a + 7 ) ( a - 8 )$
C) $( a - 7 ) ( a - 8 )$
D) $( a - 4 ) ( a + 14 )$
E) $( a + 4 ) ( a - 14 )$