9. For the equation $\sin ^{2} x+3 a^{2} \cos x-2 a^{2}(3 a-2)-1=0$ to have solutions, the range of values for $a$ is
(A) $-\frac{1}{2} \leqslant a \leqslant 1$
(B) $a>1$ or $-\frac{1}{3}<a<\frac{1}{2}$
(C) $-\frac{1}{3}<a<\frac{2}{3}$
(D) $\frac{1}{2} \leqslant a \leqslant 1$
$\mathbf{A}$