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': 'The anterior triangle occupies the side of the neck in front of sternomastoid muscle. Each triangle presents boundaries in front: \nSelect and explain. \nA. Anterior median line of the neck extending from symphysis menti to suprasternal notch., B. The midline of the neck, C. Midline of the neck up to the sternoclavicular joint, D. Posterior border of thyroid gland', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Boundaries of anterior triangle are:\nAnteriorly by the median plane.\nPosteriorly by the sternocleidomastoid.\nSuperiorly by the base of the mandible and by a line joining the angle of\nmandible to the mastoid process.\nThe apex of the triangle lies above the manubrium sterni', 'role': 'assistant'}]