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: Unknown
[{'content': 'All these are the properties of exotoxin except: \nSelect and explain. \nA. Heat stable, B. Highly antigenic, C. Neutralized by antibodies, D. Protein in nature', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (Refer: Anantha Narayanan and Paniker’s Textbook of Microbiology, 9th edition, pg no: 75)\nDifferences between Exotoxin and Endotoxin', 'role': 'assistant'}]