This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli), Subject name: Microbiology
[{'content': 'The diphtheria toxin has an affinity for all the following tissues EXCEPT \nSelect and explain. \nA. Myocardium, B. Brain, C. Adrenals, D. Liver', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The diphtheria toxin is the sole virulence factor of C. diphtheriae. Responsible for both local effects and systemic complications. It is encoded by a lysogenic beta-prophage. It inhibits mammalian protein synthesis (ribosomal function) ADP ribosylation of EF-2 It has a special affinity for myocardium, adrenals and nerve endings', 'role': 'assistant'}]