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: Medicine
[{'content': 'Hyperbaric oxygen therapy is used for the treatment of all except: \nSelect and explain. \nA. Myonecrosis., B. Osteoradionecrosis., C. Alveolar osteitis., D. Chronic osteomyelitis.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Clostridium perfringens cause gas gangrene or myonecrosis. Gas gangrene is characterized by skin\xa0colour change from pallor to bronze/purple discoloration and the skin is tense and exquisitely tender. Gas in the tissues may be obvious with crepitus on clinical examination or visible on radiograph.\nSurgical debridement, antibiotic therapy with high-dose I.V. penicillin, clindamycin and metronidazole and hyperbaric oxygen therapy are used for treating gas gangrene.\nNote: Hyperbaric\xa0oxygen therapy is also used for osteoradionecrosis and chronic osteomyelitis.\nCl. tetani causes tetanus and cl. difficile causes pseudomembranous colitis.', 'role': 'assistant'}]