Answer:
d. more permeable to sodium ions.
Step-by-step explanation:
The binding of Acetylcholine with the receptors at motor end plate facilitate membrane permeability to sodium ions therefore opening of voltage gated channels for sodium ions.
Sodium ions diffused into the synapse of post synaptic neuron at the neuromuscular junction.
If the stimulus is up to threshold levels; more chemical(neurotransmitter) gated sodium channels opens, and sodium ions move into the synapse to depolarize the membrane with reversal of charges to generate action potential.
The continuous binding of Acetycholine , leads to permanent opening of sodium ions,and over excitation from depolarization. Acetycholinesterase enzymes breakdown Acetycholine to choline and Acetyl Co -A. These are recycle back to Acetycholiine