This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Microbiology Pa 1 (History, Microscopy, Stains and Structure and Physiology of Bacteria), Subject name: Microbiology
[{'content': 'Steps of Gram stain sequence arrangement. a. Mordant- iodine treatment b. Safranin c. Crystal violet d. Alcohol wash \nSelect and explain. \nA. a>b>c>d, B. b>c>a>d, C. c>a>d>b, D. b>a>d>c', 'role': 'user'}, {'content': "Answer: C \nExplanation: Steps of Gram stain sequence arrangement. Step Name Feature 1 Primary stain Stain with crystal violet for 1 minute and rinse with water 2 Mordant Stain with gram's iodine for 1 min 3 Decolorization Acetone for 2-3 s or 95% ethanol for 20-30s 4 Counter stain Safranin for 30-60s", 'role': 'assistant'}]