Final answer:
Botulinum toxin, which causes botulism, prevents the release of acetylcholine at neuromuscular junctions, resulting in flaccid paralysis.
Step-by-step explanation:
The toxin that causes botulism is botulinum toxin, commonly referred to as botox. This toxin is a neurotoxic protein produced by the bacterium Clostridium botulinum and related species. It functions by preventing the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction, leading to flaccid paralysis. The correct option is that botulinum toxin prevents release of acetylcholine.