The number of distinct real roots of $\begin{vmatrix}\sin x&\cos x&\cos x\\\cos x&\sin x&\cos x\\ \cos x&\cos x&\sin x\end{vmatrix}=0$ in the interval $-\large\frac{\pi}{4}$$\leq x\leq \large\frac{\pi}{4}$ is

Question

$(a)\;0\qquad(b)\;2\qquad(c)\;1\qquad(d)\;3$