text: <unk>  <unk>  is a virus found around the world. It is related to the viruses that cause chickenpox and infectious mononucleosis (mono). Between 50 percent and 80 percent of adults in the United States have had a<unk>  by age 40. Once<unk>  is in a person's body, it stays there for life.<unk>  is spread through close contact with body fluids. Most people with<unk>  don't get sick and don't know that they've been infected. But infection with the virus can be serious in babies and people with weak immune systems. If a woman gets<unk>  when she is pregnant, she can pass it on to her baby. Usually the babies do not have health problems. But some babies can develop lifelong disabilities.
option_0: Cytomegalovirus infection
option_1: AIDS
option_2: Chlamydia infection
option_3: Adenovirus infection
option_4: Pneumococcal infections
option_5: Vaccinia
option_6: Toxocara infection
option_7: Syphilis