If $\omega$ is a complex cube root of unity, then the product of $\left(1-\omega+\omega^{2}\right)\left(1-\omega^{2}+\omega^{4}\right)\left(1-\omega^{4}+\omega^{8}\right) \ldots$ to 20 factors is equal to
(a) $4^{10}$
(b) $4^{20}$
(c) $(4 \omega)^{10}$
(d) $\left(\frac{4}{\omega}\right)^{10}$