input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A previously healthy 16-year-old boy comes to the physician because of a 5-day history of pain at the back of his left ankle. His mother had a myocardial infarction at 54 years. His BMI is 23 kg/m2. There is tenderness above the left posterior calcaneus and a firm, 3-cm, skin-colored nodule that moves with the left Achilles tendon. A photomicrograph from a biopsy of the nodule is shown. Serum studies in this patient are most likely to show increased levels of which of the following?   (A) Rheumatoid factor   (B) Angiotensin converting enzyme   (C) Low-density lipoprotein   (D) Triglycerides
output: ['(C) Low-density lipoprotein <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Rheumatoid factor  (B) Angiotensin converting enzyme  (C) Low-density lipoprotein  (D) Triglycerides <> possible answers', '  A previously healthy 16-year-old boy comes to the physician because of a 5-day history of pain at the back of his left ankle. His mother had a myocardial infarction at 54 years. His BMI is 23 kg/m2. There is tenderness above the left posterior calcaneus and a firm, 3-cm, skin-colored nodule that moves with the left Achilles tendon. A photomicrograph from a biopsy of the nodule is shown. Serum studies in this patient are most likely to show increased levels of which of the following? <> context']