Multiply and Then, If Possible, Simplify by Factoring $\sqrt{3 x^{2} y} \sqrt{6 x^{7} y^{4}}$

Multiple Choice

Multiply and then, if possible, simplify by factoring.
- $\sqrt{3 x^{2} y} \sqrt{6 x^{7} y^{4}}$

A) $9 x^{8} y^{4} \sqrt{2 x y}$
B) $3 x^{4} y^{2} \sqrt{2}$
C) $3 x^{4} y^{2} \sqrt{2 x y}$
D) $3 \sqrt{2 x^{9} y^{5}}$