What Evidence Suggests That While Viruses May Play a Role

What evidence suggests that while viruses may play a role in cancer development and increase a person's risk of developing cancer, they are rarely the sole determinant responsible for the disease?

A) Human papilloma virus (HPV) is transmitted by sexual intercourse.
B) Although HPV is found in ~90% of human cervical cancers, most women infected with the virus never develop the cancer.
C) HPV is found in ~90% of human cervical cancers, and women infected with the virus develop the cancer.
D) All women infected with HPV develop cervical cancer.