<prompt> 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:PoliomyelitisBotulismDiphtheriaPorphyria  <response>: Ans. is b i.e., BotulismRef: Harrison, 18the, p. 1201 and 17the, 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. 