This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
[{'content': 'Narrowest part of male urethra - \nSelect and explain. \nA. Prostatic, B. Membranous, C. Spongy, D. Penil', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Membranous o Narrowest and least dilatable part of male urethra - membranous urethra.o Widest and most dilatable part of male urethra - Prostatic urethra.o Shortest part of male urethra - Membranous urethra.o Longest part of male urethra - Penile urethra.", 'role': 'assistant'}]