This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
True about exotoxins - 
Select and explain. 
A. Lipopolysaccharide, B. Not antigenic, C. Can be toxoided, D. Heat stable
C: Can be toxoided
Answer: C: Can be toxoided 
Explanation: EXOTOXINS: Proteins heat labile actively secreted by cells diffuse into surrounding medium readily separable from cultures by physical means such as filtration action often enzymatic specific pharmacological effects for each exotoxinspecific tissue affinities active in very minutes dose highly antigenic action specifically neutralized by antibody Ref Ananthanarayan & paniker's Textbook of Microbiology 9th edition pg no 75