6. Let $\omega$ be a complex cube root of unity, then the value of $(1-\omega)\left(1-\omega^{2}\right)\left(1-\omega^{4}\right)\left(1-\omega^{8}\right)$ is
A. $\omega$
B. $\bar{\omega}$
C. 9
D. 6
6. $\mathrm{C}$ Original expression $=(1-\omega)^{2}\left(1-\omega^{2}\right)^{2}=\left(1-\omega-\omega^{2}+\omega^{3}\right)^{2}=(3)^{2}=9$