The coefficient of $x^{n}$ in the product $(1-x)(1-2 x)\left(1-2^{2} \cdot x\right)\left(1-2^{3} \cdot x\right) \ldots\left(1-2^{n}+x\right)$ is
equal to
$($ A $)\left(1-2^{n+1}\right) 2^{\frac{n(n-1)}{2}}$.
(B) $\left(2^{n+1}-1\right) \cdot 2^{\frac{n(n-1)}{2}}$
(C) $\left(1-2^{n}\right) 2^{\frac{n(n-1)}{2}}$.
(D) None of these