In the Process of Chromosome Separation,how Do Microtubules Maintain Contact

Multiple Choice

In the process of chromosome separation,how do microtubules maintain contact with the kinetochores and shorten at the same time?

A) Motor proteins move chromosomes down the microtubular structures of the mitotic spindle.
B) Actin microfilaments cause the microtubular proteins to slide past each other.
C) The centrosomes move apart,so the microtubular proteins do not need to shorten.
D) The centrosomes create the shortening/depolymerization of the microtubular proteins.