**Core Concept**
The resting membrane potential (RMP) of a cell is the difference in electrical charge between the inside and outside of a cell when it is at rest. It is primarily generated by the movement of ions, particularly potassium (K+) and sodium (Na+), across the cell membrane.

**Why the Correct Answer is Right**
The RMP is primarily determined by the movement of potassium ions out of the cell through potassium leak channels. This movement is driven by the concentration gradient of potassium ions, with a higher concentration inside the cell. As potassium ions leave the cell, they carry a positive charge with them, leaving the inside of the cell negatively charged relative to the outside. The RMP is typically around -70 millivolts (mV) in most mammalian cells.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not accurately describe the primary mechanism behind the RMP.
* **Option B:** This option is incorrect because it does not specify the direction of ion movement and the resulting charge distribution.
* **Option C:** This option is incorrect because it does not accurately describe the role of potassium ions in generating the RMP.

**Clinical Pearl / High-Yield Fact**
The RMP is a critical parameter in understanding the behavior of cells, particularly in the context of cardiac arrhythmias and seizures. A shift in the RMP can have significant consequences for cellular function and overall health.

**Correct Answer:** C. The resting membrane potential (RMP) is primarily generated by the movement of potassium (K+) ions out of the cell.