Factor Completely Using the Grouping Method to Factor Trinomials $$36 x ^ { 2 } + 21 x y + 3 y ^ { 2 }$$

Multiple Choice

Factor completely using the grouping method to factor trinomials. If unfactorable, indicate that the polynomial is prime.
- $$36 x ^ { 2 } + 21 x y + 3 y ^ { 2 }$$

A) $3 ( 3 x + y ) ( 4 x + y )$
B) prime
C) $3 ( 3 x - y ) ( 4 x - y )$
D) $( 9 x + 3 y ) ( 4 x + y )$