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
Exotoxins are - 
Select and explain. 
A. Lipopolysaccharide in nature, B. Produced by gram -ve bacilli, C. Highly antigenic, D. Very stable and resistant to chemical agents
C: Highly antigenic
Answer: C: Highly antigenic 
Explanation: Exotoxins are protein in nature
Produced by both gram (+) ve and gram (-) ve bacteria
They are highly antigenic
They are sensitive to chemical agents like formaldehyde and can be toxoided.