40. A researcher applies a drug that prevents neurotransmitter release from the presynaptic terminal without affecting action potential propagation. Which change would most likely be observed in the postsynaptic cell? (A) Voltage-gated Ca²⁺ channels would remain closed. (B) Ligand-gated ion channels would fail to open. (C) Resting membrane potential would become more positive. (D) Voltage-gated Na⁺ channels would remain permanently inactivated.