The Ability of Some Viruses to Remain Inactive (Latent)for a Period

The ability of some viruses to remain inactive (latent) for a period of time is exemplified by

A) influenza,a particular strain of which returns every 10-20 years.
B) herpes simplex viruses (oral or genital) ,whose reproduction is triggered by physiological or emotional stress in the host.
C) Kaposi's sarcoma,which causes a skin cancer in people with AIDS but rarely does so in those not infected by HIV.
D) the virus that causes a form of the common cold,which recurs in patients many times in their lives.