This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
[{'content': "This patient's serum was found to be discolored four hours following a surgical procedure. What is the most likely cause? \nSelect and explain. \nA. Fluorescent dye, B. Methemoglobinemia, C. Propofol, D. Pseudomonal sepsis", 'role': 'user'}, {'content': "Answer: A \nExplanation: Answer A. Fluorescent dyeThe patient had undergone intraoperative angiography with a fluorescent dye and a Wood's lamp was used to evaluate mesenteric-vessel viability.", 'role': 'assistant'}]