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: Anatomy
[{'content': 'Which of the following cartilage has signet ring shape - \nSelect and explain. \nA. Thyroid, B. Cricoid, C. Cuneiform, D. Arytenoid', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Cricoid cartilage is the only cartilage forming a complete ring, therefore is shaped like a ring.', 'role': 'assistant'}]