input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A group of researchers wants to evaluate how often the human immunodeficiency virus (HIV) is related to high-risk behaviors in female sex workers from their country. An additional aim is to evaluate the association between HIV acquisition and certain sociodemographic factors. The researchers collect data through interviewer-administered questionnaires (for behavioral and sociodemographic data) as well as through clinical and serological evaluation/screening methods for HIV and other sexually transmitted infections. Which of the following could be the main outcome measure of their study?   (A) Incidence   (B) Prevalence   (C) Hazard rate   (D) Attributable risk
output: ['(B) Prevalence <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Incidence  (B) Prevalence  (C) Hazard rate  (D) Attributable risk <> possible answers', '  A group of researchers wants to evaluate how often the human immunodeficiency virus (HIV) is related to high-risk behaviors in female sex workers from their country. An additional aim is to evaluate the association between HIV acquisition and certain sociodemographic factors. The researchers collect data through interviewer-administered questionnaires (for behavioral and sociodemographic data) as well as through clinical and serological evaluation/screening methods for HIV and other sexually transmitted infections. Which of the following could be the main outcome measure of their study? <> context']