You experimentally apply ?-bungarotoxin to a muscle and find that it does not contract when you electrically stimulate the motor neuron leading to it. You know that this toxin blocks acetylcholine receptors. Therefore, you suspect that the stimulation of contraction is failing at which of the following points?
A. A contraction fails to occur because acetylcholine is not released from the motor neuron.
B. A contraction fails to occur because an action potential is not generated in the muscle cell.
C. A contraction fails to occur because this toxin directly prevents calcium ion release from intracellular stores.
D. A contraction fails to occur because neurotransmitter release by the motor neuron is blocked at the neuromuscular junction.
E. A contraction fails to occur because this toxin prevents cross-bridge formation and thereby directly prevents contraction.
B. A contraction fails to occur because an action potential is not generated in the muscle cell.
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