This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
[{'content': 'Opacity around colonies of Clostridium perfringens is due to: \nSelect and explain. \nA. Theta toxin, B. Lecithinase, C. Desmolase, D. Cytokinin', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Lecithinase(Ref: Ananthanarayan, 9th/e, p. 251-255 and 8th/e, p. 252-253)Naegler's reaction: This reaction is produced by C. perfringens as opalescence in 20% human serum or egg yolk media due to Lecithinase (phospholipase) activity of alpha toxin, it splits lecithin into phosphorylcholine and diacylgly- cerol in the presence of Ca++and Mg++ ions.", 'role': 'assistant'}]