Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor tubulin. Surprisingly, this stops mitosis. Specifically, Taxol must affect
A) chromatid assembly.
B) the fibers of the mitotic spindle.
C) anaphase.
D) the S phase of the cell cycle.
E) formation of the centrioles.