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: Microbiology
[{'content': 'Exotoxins are - \nSelect and explain. \nA. Lipopolysaccharide in nature, B. Produced by gram -ve bacilli, C. Highly antigenic, D. Very stable and resistant to chemical agents', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Exotoxins are protein in nature\nProduced by both gram (+) ve and gram (-) ve bacteria\nThey are highly antigenic\nThey are sensitive to chemical agents like formaldehyde and can be toxoided.', 'role': 'assistant'}]