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: Pathology
[{'content': "Ludwig's angina usually begins in which of the following space? \nSelect and explain. \nA. Submandibular space, B. Sublingual space, C. Submental space, D. All of the above", 'role': 'user'}, {'content': "Answer: A \nExplanation: Ludwig's angina is an acute, potentially life threatening, toxic cellulitis, beginning usually in the submandibular space and secondarily involving the sublingual and submental spaces as well. The disease is not usually considered to be true Ludwig’s angina unless all submandibular spaces are involved.\xa0\nRef: Shafer's textbook of oral pathology 7th edition page 510", 'role': 'assistant'}]