## Core Concept
Cardiac output (CO) is the volume of blood the heart pumps per minute. It is a critical parameter in cardiovascular physiology. The relationship between cardiac output, heart rate (HR), and stroke volume (SV) is fundamental.

## Why the Correct Answer is Right
Cardiac output (CO) is calculated as the product of heart rate (HR) and stroke volume (SV): CO = HR × SV. When cardiac output is divided by heart rate, the stroke volume is obtained: CO / HR = SV. Stroke volume represents the volume of blood pumped by the left ventricle of the heart in one contraction. Therefore, when you divide cardiac output in L/min by heart rate in beats per minute (bpm), you get the stroke volume in milliliters (mL) or liters (L), which is typically expressed as mL/beat.

## Why Each Wrong Option is Incorrect
**Option A:** This option is incorrect because it does not accurately represent the result of dividing cardiac output by heart rate.
**Option B:** This option suggests another parameter but is not the direct result of the division in question.
**Option D:** This option is incorrect as it does not correctly represent the physiological parameter derived from dividing cardiac output by heart rate.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that stroke volume (SV) is an essential indicator of cardiac function. Normal stroke volume for an average adult is approximately 70 mL/beat. Changes in stroke volume can indicate alterations in cardiac function, which can be critical in diagnosing and managing cardiovascular diseases.

**Correct Answer:** .