This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Testis and scrotum, Subject name: Surgery
[{'content': 'What is the grade of given varicocele? \nSelect and explain. \nA. Subclinical, B. Grade I, C. Grade II, D. Grade III', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Varicocele Classification Subclinical Not palpable or visible at rest or during Valsalva maneuver, but demonstrable by special testsQ (reflux found on doppler examination) Grade 1 Palpable during ValsalvaQ maneuver, but not otherwise Grade 2 Palpable at restQ, but not visible Grade 3 VisibleQ and palpable at rest', 'role': 'assistant'}]