Botulinum toxin blocks the release of acetylcholine from cholinergic nerve terminals. Which is a possible effect of botulinum toxin?

Botulinum toxin, produced by the bacterium Clostridium botulinum, inhibits the release of acetylcholine at the neuromuscular junction by preventing the fusion of acetylcholine-containing vesicles with the presynaptic membrane. Since acetylcholine is critical for muscle contraction, its blockage leads to paralysis of skeletal muscles. This is why the possibility of skeletal muscle paralysis is a direct and significant effect of botulinum toxin.

Unlike the other options that suggest enhancing or increasing neuromuscular function or activity, skeletal muscle paralysis directly correlates with the mechanism of action of botulinum toxin. In therapeutic settings, this property is harnessed for the treatment of conditions characterized by excessive muscle contractions, but its toxic effects can result in severe paralysis when not used appropriately.