Mutations in Genes That Encode Components of DNA-Repair Systems Are

Mutations in genes that encode components of DNA-repair systems are often associated with cancer; these mutations increase the rate at which mutations are retained and result in an increased number of mutations in proto-oncogenes, tumor-suppressor genes, and other genes that contribute to cell proliferation. Mutations that allow telomerase to be expressed in somatic cells and those that affect vascularization and metastasis also may contribute to cancer progression.
-Which type of mutation in telomerase could be associated with cancer cells?

A) Mutations that produce an inactive form of telomerase
B) Mutations that decrease the expression of telomerase
C) Mutations that increase the expression of telomerase
D) All of the above