**Core Concept**
Mean arterial pressure (MAP) is a critical hemodynamic parameter that reflects the net pressure exerted by the arterial circulation on the vascular bed. It is a measure of the pressure in the aorta and large arteries during one cardiac cycle, and it is an important determinant of tissue perfusion and oxygen delivery.

**Why the Correct Answer is Right**
The correct formula for calculating MAP is: MAP = (2/3) x (diastolic blood pressure + systolic blood pressure). This formula is based on the concept that diastolic blood pressure is more representative of the pressure in the peripheral circulation, while systolic blood pressure is more representative of the pressure in the aorta. The two-thirds factor is used to weight the diastolic pressure more heavily, as it is a better predictor of tissue perfusion.

**Why Each Wrong Option is Incorrect**
**Option A:** The formula for calculating MAP is not simply the average of systolic and diastolic blood pressures, as it does not take into account the pulsatile nature of blood pressure.
**Option B:** The formula for calculating MAP is not the same as the formula for calculating pulse pressure, which is the difference between systolic and diastolic blood pressures.
**Option C:** The formula for calculating MAP is not the same as the formula for calculating cardiac output, which is the product of stroke volume and heart rate.

**Clinical Pearl / High-Yield Fact**
In clinical practice, MAP is an important parameter to monitor, especially in critically ill patients or those with cardiovascular disease. A low MAP can lead to inadequate tissue perfusion and organ dysfunction, while a high MAP can lead to increased cardiac workload and potential cardiac damage.

**Correct Answer: C. (2/3) x (diastolic blood pressure + systolic blood pressure)**