Factor by Grouping $$13 x ^ { 2 } + 91 x - 3 x - 21$$

Multiple Choice

Factor by grouping. $$13 x ^ { 2 } + 91 x - 3 x - 21$$

A) $( 13 x - 3 ) ( x + 7 )$
B) $13 x ( x + 7 ) - 3 ( x + 7 )$
C) $13 x ( x + 7 ) - 3 x + 21$
D) $( 13 x - 3 ) ( x - 21 )$
E) $13 x ^ { 2 } + 91 x - 3 ( x + 7 )$