The equation $x^3 y + x y^3 + x y = 0$ represents (A) a circle (B) a circle and a pair of straight lines (C) a rectangular hyperbola (D) a pair of straight lines
The equation $x^3 y + x y^3 + x y = 0$ represents\\
(A) a circle\\
(B) a circle and a pair of straight lines\\
(C) a rectangular hyperbola\\
(D) a pair of straight lines