This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Male Genital System, Subject name: Anatomy
[{'content': 'Normal volume of adult testis- \nSelect and explain. \nA. 5-10ml, B. 10-15ml, C. 15-20 ml, D. 25-30 ml', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. is \'c\' i.e., 15-20 ml "Normal adult testicular volume is 15-20 ml, calculated by the formula : length x width x depth x 0-52 = volume" - Grainger.', 'role': 'assistant'}]