This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'True about Tanner stage 3, \nSelect and explain. \nA. Penis increases in length, B. Penis increases in width, C. Scanty hair at the base of the penis, D. Darkening of scrotum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tanner staging of sexual maturity in boys STAGE 1 - Testicular volume <3ml(prepubeal) STAGE 2 - Reddening of scrotum, testicular volume reaching 4 ml, scanty hair at penile base. STAGE 3 - Increase in the length of penile shaft, fuher increase in testicular volume, pubic hair begins to curl and darken. STAGE 4 - Increase in the gih of penis and glans, Darkening of scrotum, Coarse abundant and curly pubic hair STAGE 5 - Adult size scrotum and penis, Adult type pubic hair spreading over to medial thighs. Ref: GHAI , 9th edition, Page 61.', 'role': 'assistant'}]