This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
[{'content': 'in the aboove show triangle posteror border is formed by ? \nSelect and explain. \nA. bony labrynth, B. sigmoid sinus, C. superior petrosal sinus, D. CAVERNOUS SINUS', 'role': 'user'}, {'content': 'Answer: B \nExplanation: THIS IS THE IMAGE OF TRAUGHTMANNS TRIAGNLE REF : GRAYS ANATOMY', 'role': 'assistant'}]