This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuroanatomy, Subject name: Anatomy
[{'content': 'Leptomeninges is formed by: \nSelect and explain. \nA. Dura mater and Arachnoid, B. Arachnoid and pia mater, C. Dura and pia mater, D. Dura, arachnoid and pia matter', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. B Arachnoid and pia materRef: Netter's Clinical Anatomy, 3rd ed. pg. 25* Meninx implies all three layers--dura, arachnoid and inner pia matter.* The dura mater is called pachymeninx.* The middle arachnoid and inner pia matter is called as leptomeninges.* The arachnoid does not follow the convolutions of brain and looks like a loose fitting sac. Multiple arachnoid granulations pass through subarachnoid space and blends with pia matter.", 'role': 'assistant'}]