The function of `Na^(+)` and `k^(+)` pump is to

Options

A. `Na^(+)` out and `Cl^(-)` in
B. `Cl^(-)` out and `Na^(+)` in
C. `Na^(+)` in and `k^(+)` out
D. `Na^(+)` out and `K^(+)` in

Answer

### Step-by-Step Solution:

1. **Identify the Pump**: The sodium-potassium pump (Na⁺/K⁺ pump) is a membrane protein found in the cell membrane of neurons and other cells.

2. **Location of the Pump**: This pump is primarily located in the axon of neurons, which are specialized cells for transmitting nerve impulses.

3. **Understanding Concentration Gradients**: In the extracellular fluid (ECF), there is a higher concentration of sodium ions (Na⁺), while in the intracellular fluid (ICF), there is a higher concentration of potassium ions (K⁺).

4. **Function of the Pump**: The sodium-potassium pump works against these concentration gradients. It actively transports sodium ions out of the cell and potassium ions into the cell.

5. **Active Transport Mechanism**: The pump requires energy in the form of ATP to function, as it is moving ions against their concentration gradients. Specifically, it moves 3 sodium ions out of the cell and 2 potassium ions into the cell.

6. **Final Outcome**: The result of this process is that there is a net movement of positive charge out of the cell, which is crucial for maintaining the resting membrane potential and for the generation of action potentials in neurons.

### Conclusion:
The function of the sodium-potassium pump is to transport 3 sodium ions (Na⁺) out of the cell and 2 potassium ions (K⁺) into the cell, thus maintaining the electrochemical gradient essential for nerve impulse transmission.

---