This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brain , Subject name: Anatomy
[{'content': 'Internal carotid aery crosses \nSelect and explain. \nA. Sigmoid sinus, B. Straight sinus, C. Cavernous sinus, D. Saggital sinus', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Inside the middle cranial fossa, it first runs forwards along the floor and medial wall of the cavernous sinus and then turns upwards on the medial side of the anterior clinoid process.(Ref: Vishram Singh textbook of clinical neuroanatomy second edition pg 175)', 'role': 'assistant'}]