This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'Which of the following rib is known as floating rib? \nSelect and explain. \nA. 8, B. 9, C. 10, D. 11', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. D 11Ref: Netter's Clinical Anatomy, 3rd ed. pg. 89* The 11th and 12th ribs are floating ribs as they are free at their ends.* The 8th, 9th and 10th ribs are false ribs as they are joined to form cartilage of rib immediately above.* The first 7 pair of ribs are true ribs.", 'role': 'assistant'}]