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: Gynaecology & Obstetrics
[{'content': 'Which of the following describes the pelvic outlet \nSelect and explain. \nA. Angle of pubic arch is less than 90 degrees., B. Base of posterior triangle is the coccyx., C. Descending inferior pubic rami form lateral boundaries of posterior triangle., D. Common base of the two triangles is formed by a line drawn between the two ischial tuberosities.', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Pelvic outlet consists of 2 triangular areas with a common base, which is a line drawn between the two ischial tuberosities.\nAngle of pubic arch is 90\xa0→ 100 degrees.\nLateral boundaries of posterior triangle is formed by sacrotuberous ligaments.', 'role': 'assistant'}]