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': 'Upper border of posterior belly of digastric is related to: \nSelect and explain. \nA. Posterior auricular artery., B. Occipital artery., C. Ascending pharyngeal artery., D. Lingual artery.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The upper border of posterior belly of digastric is related to "posterior auricular artery" while its lower border is related to "occipital artery".', 'role': 'assistant'}]