This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'A wound specimen obtained from a person working with wool from a Caribbean island demonstrated a large gram-positive rod from a non- hemolytic colony with swirling projections on blood agar. The most likely method to demonstrate spores would be which of the following \nSelect and explain. \nA. Gram stain, B. Acid-fast stain, C. India ink stain, D. Malachite green stain', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Spores can be observed as intracellular refractile bodies in unstained cell suspensions. Also, they are commonly observed by staining with malachite green or carbolfuchsin. The spore wall is relatively impermeable, but heating of the preparation allows dyes to penetrate. Alcohol treatment then serves to prevent spore decolorization. Finally, the spores are counterstained.', 'role': 'assistant'}]