Solve the equation on the interval $0 \le \theta < 2\pi$.
$\sqrt{2} \cos(2\theta) = 1$
A. No solution
B. $\left\{\frac{\pi}{4}, \frac{3\pi}{4}, \frac{5\pi}{4}, \frac{7\pi}{4}\right\}$
C. $\left\{\frac{\pi}{8}, \frac{7\pi}{8}, \frac{9\pi}{8}, \frac{15\pi}{8}\right\}$
D. $\left\{0, \frac{2\pi}{3}, \pi, \frac{4\pi}{3}\right\}$