Factor the Trinomial Completely $x^{2}+4 x y-21 y^{2}$ A) $(x-7 y)(x+3 y)$

Multiple Choice

Factor the trinomial completely.
- $x^{2}+4 x y-21 y^{2}$

A) $(x-7 y) (x+3 y)$
B) $(x-y) (x+3 y)$
C) $(x-7 y) (x+y)$
D) $(x+7 y) (x-3 y)$