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
Diphtheria toxin acts by: 
Select and explain. 
A. Inhibiting acetyl choline release, B. Inhibiting glucose transport, C. Increasing levels of cyclic AMP, D. Inhibiting protein synthesis
D: Inhibiting protein synthesis
Answer: D: Inhibiting protein synthesis 
Explanation: Ans. is 'd' i.e., Inhibiting protein synthesis(Ref: Ananthanarayan, 9th/e, p. 238 and 8th/e, p. 234)An exotoxin with a similar mode of action can be produced by strains of Pseudomonas aeruginosa.