$\cos\large\frac{\pi}{11}$$\cos\large\frac{2\pi}{11}$$\cos\large\frac{3\pi}{11}..........$$\cos\large\frac{11\pi}{11}$ is equal to

Question

$(a)\;-\large\frac{1}{32}$$\qquad(b)\;\large\frac{1}{512}$$\qquad(c)\;\large\frac{1}{1024}$$\qquad(d)\;-\large\frac{1}{2048}$