Question

abrupt change from a negative to a positive charge of a nerve cell
muscle fiber
axon terminal
motor neuron
muscle contraction
action potential

Explanation:

An action potential is the abrupt change from a negative to a positive charge of a nerve cell. Muscle fibers are related to muscle tissue, axon terminals are parts of neurons for neurotransmitter release, motor neurons are a type of neuron for muscle - control, and muscle contraction is a process in muscle function, none of which directly describe the charge change in a nerve cell.

Answer:

E. action potential