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': 'Diphtheria toxin acts by - \nSelect and explain. \nA. Inhibiting acetyl choline release, B. Inhibiting glucose transport, C. Increasing levels of cyclic AMP, D. Inhibiting protein systhesis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]