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': 'Iliac crest at the level of (highest point) - \nSelect and explain. \nA. L3, B. L4, C. L5, D. S1', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]