For $0 \leq x < 2 \pi$, the number of solutions of the equation $$\sin ^ { 2 } x + 2 \cos ^ { 2 } x + 3 \sin x \cos x = 0$$ is (A) 1 . (B) 2 . (C) 3 . (D) 4 .
For $0 \leq x < 2 \pi$, the number of solutions of the equation
$$\sin ^ { 2 } x + 2 \cos ^ { 2 } x + 3 \sin x \cos x = 0$$
is\\
(A) 1 .\\
(B) 2 .\\
(C) 3 .\\
(D) 4 .