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': 'Which of the following is the largest foramen of skull? \nSelect and explain. \nA. Foramen lacerum, B. Foramen magnum, C. Foramen ovale, D. Foramen spinosum', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The foramen magnum is the largest foramen of the skull. It opens upwards into the posterior cranial fossa, and downwards into the vertebral canal. It is oval in shape, being wider behind than in front\xa0 where it is overlapped on each side by the occipital condyles.', 'role': 'assistant'}]