The set of all solutions of the equation $\cos 2\theta = \sin \theta + \cos \theta$ is given by\\
(A) $\theta = 0$\\
(B) $\theta = n\pi + \frac{\pi}{2}$, where $n$ is any integer\\
(C) $\theta = 2n\pi$ or $\theta = 2n\pi - \frac{\pi}{2}$ or $\theta = n\pi - \frac{\pi}{4}$, where $n$ is any integer\\
(D) $\theta = 2n\pi$ or $\theta = n\pi + \frac{\pi}{4}$, where $n$ is any integer