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
An 18-year-old male presented with acute onset descending paralysis of 3 days duration. There is also history of blurring of vision for the same duration. On examination, the patient has quadriparesis with areflexia. Both the pupils are non-reactive. The most probably diagnosis is: 
Select and explain. 
A. Poliomyelitis, B. Botulism, C. Diphtheria, D. Porphyria
B: Botulism
Answer: B: Botulism 
Explanation: Ans. is 'b' i.e., Botulism(Ref: Harrison, 18th/e, p. 1201 and 17th/e, p. 901)* Acute descending paralysis, are areflexia, blurring of vision and non-reactive pupils suggest the diagnosis of botulism.* Diphtheria, polio and porphyria do not present with non-reactive pupil.