A 22-year-old male presents to his primary care clinic for an annual examination. He reports his only past medical history is having hepatitis A during a trip to Mexico two years prior from which he fully recovered. His social history is notable for marijuana use. He reports having sex only with male partners. Among men who have sex with men, which one of the following factors has been epidemiologically linked to an increased risk of sexual acquisition of hepatitis C virus (HCV)? A prior history of rectal chlamydia HIV infection Age older than 45 years Marijuana use prior to having sex