Factor Completely Using the Grouping Method to Factor Trinomials $14 x ^ { 2 } - 49 x - 28$

Multiple Choice

Factor completely using the grouping method to factor trinomials. If unfactorable, indicate that the polynomial is prime.
- $14 x ^ { 2 } - 49 x - 28$

A) $7 ( 2 x + 1 ) ( x - 4 )$
B) prime
C) $( 14 x - 7 ) ( x + 4 )$
D) $7 ( 2 x - 1 ) ( x + 4 )$