The Area of a Square Is Given by the Polynomial $25 x^{2}+30 x y+9 y^{2}$

Multiple Choice

The area of a square is given by the polynomial $25 x^{2}+30 x y+9 y^{2}$ . Find the length of a side of the square in terms of $x$ and $y$ .

A) $25 x^{2}+31 y$
B) $25 x^{2}+9 y^{2}$
C) $25 x^{2}+25 x y+6 y^{2}$
D) $5 x+3 y$