This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
[{'content': 'Nerve to pterygoid canal is formed from \nSelect and explain. \nA. Deep petrosal nerve + greater petrosal nerve, B. Facial nerve, C. Lesser superficial petrosal nerve, D. Lesser petrosal nerve', 'role': 'user'}, {'content': "Answer: A \nExplanation: In the anterior pa of the foramen lacerum, the greater petrosal nerve unites with the deep petrosal nerve to form the nerve of the pterygoid canal which leaves the foramen by entering the pterygoid canal in the anterior wall of the foramen lacerum. Ref: BD Chaurasia's HUMAN ANATOMY, Volume 3, 4th edition.", 'role': 'assistant'}]