The original membrane potential of a resting neuron is _____.a. $-70\mathrm{mV}$b. $+190\mathrm{mV}$c. sodiumd. ATP

Step by Step Solution: Step 1. The original membrane potential of a resting neuron is the electrical potential difference across the neuronal membrane when the neuron is not transmitting signals. Step 2. This resting potential is maintained by the positively charged potassium ions (K+) inside the neuron and the negatively charged chloride ions (Cl-) & large negatively charged proteins on the outside of the neuron. Step 3. The resting potential of a typical neuron is around -70mV (millivolts), which means that the inside of the neuron is 70mV less than the outside. So, the correct answer is option a. $-70\mathrm{mV}$. Step 4. Option b is incorrect because $+190\mathrm{mV}$ is a very high value and not feasible for a resting neuron. Option c is incorrect because sodium ions (Na+) play an important role in the transmission of an action potential (nerve impulse) in an active neuron and not in maintaining its resting potential. Option d is incorrect because ATP (Adenosine triphosphate) is an energy molecule and does not contribute towards the resting potential of a neuron. Final Answer: -70mV