Two Electrodes, One on Either Side of the Cell Membrane

Multiple Choice

Two electrodes, one on either side of the cell membrane of a resting neuron, show a difference of about ‒65 mV.If the value changes quickly to about +50 mV and then rapidly returns to ‒65 mV, the most likely explanation is that

A) the cell membrane briefly became hyperpolarized.
B) a graded potential passed by the electrodes.
C) an action potential was triggered by changes in voltage-gated Na⁺ and K⁺ channels.
D) voltage-gated Na⁺ channels closed, causing a spike of depolarization, and then opened again.
E) leak K⁺ channels opened and then closed.