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
Which of the following is the largest foramen of skull? 
Select and explain. 
A. Foramen lacerum, B. Foramen magnum, C. Foramen ovale, D. Foramen spinosum
B: Foramen magnum
Answer: B: Foramen magnum 
Explanation: 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  where it is overlapped on each side by the occipital condyles.