The resting membrane potential is maintained by
a.Ion leak
b.Neurotransmitter
c Ion pump
d.Both A and C

Hint: The resting membrane cell is the static membrane potential of the quiescent cell. It is maintained by active transport and passive diffusion of ions.

Complete answer:
Let's discuss the above option and find the correct answer:
Complete step-by-step answer:
A. Ion leak: The potassium channels open and the cell becomes hyperpolarized at the peak of the action potential. The potassium ions get stored inside the cell because of the net movement with the concentration gradient when the membrane is at rest. As a result, the potassium ions leak from the cell.
B. Neurotransmitter: It is a chemical messenger that transfers a message from the nerve cell across the synapse to the target organs. They are the chemicals prepared by the nerve cell mainly to transfer messages. It is synthesised in and released from the nerve ending into the synaptic cleft.
C. Ion pump: An event takes place in which it activates the polarization of the cell body. It is maintained by active transport of ions against their electrochemical gradient by the sodium-potassium pump. These are the carrier proteins which are located in the surface membrane of the cell.
So, the resting potential membrane is maintained by both ion leak and ion pump.
Hence, the correct option is D.

Note: The outer membrane of axolemma is positively charged while the inner membrane of axolemma is negatively charged. As a result of the active transport and the diffusion process, a positive charge is more outside while the negative charge is more inside.