The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A 44-year-old man comes to the clinic because of a 6-month history of progressive fatigue. He has a history of intravenous heroin use. Physical examination shows scleral icterus. A serum study is positive for hepatitis C RNA. Therapy with interferon-α is initiated in combination with a second drug. The expected beneficial effect of the additional drug is most likely due to inhibition of which of the following enzymes?   (A) Inosine monophosphate dehydrogenase   (B) DNA-dependent RNA polymerase   (C) DNA gyrase   (D) Dihydroorotate dehydrogenase
['(A) Inosine monophosphate dehydrogenase <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Inosine monophosphate dehydrogenase \n (B) DNA-dependent RNA polymerase \n (C) DNA gyrase \n (D) Dihydroorotate dehydrogenase <> possible answers', '  A 44-year-old man comes to the clinic because of a 6-month history of progressive fatigue. He has a history of intravenous heroin use. Physical examination shows scleral icterus. A serum study is positive for hepatitis C RNA. Therapy with interferon-α is initiated in combination with a second drug. The expected beneficial effect of the additional drug is most likely due to inhibition of which of the following enzymes? <> context@']