**Core Concept**
Stroke volume (SV) refers to the amount of blood ejected by the left ventricle of the heart in one contraction, typically measured in milliliters (mL) or milliliters per beat (mL/beat). It is a critical determinant of cardiac output, which is the total volume of blood pumped by the heart per minute.

**Why the Correct Answer is Right**
Stroke volume is influenced by several factors, including preload (the initial stretching of the cardiac myocytes prior to contraction), contractility (the intrinsic ability of the heart muscle to contract), and afterload (the resistance to ejection of blood from the ventricle). According to the Frank-Starling law of the heart, an increase in preload leads to an increase in stroke volume, as the heart muscle is stretched, allowing for a more forceful contraction. This relationship is crucial for maintaining adequate cardiac output, especially in conditions such as heart failure.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the relationship between heart rate and stroke volume. While a faster heart rate can increase cardiac output, it does so by increasing the number of contractions per minute, rather than directly affecting stroke volume.
**Option B:** This option is incorrect because it misrepresents the effect of afterload on stroke volume. Afterload actually increases the resistance to ejection of blood from the ventricle, which can decrease stroke volume, not increase it.
**Option C:** This option is incorrect because it provides a misleading definition of stroke volume. While stroke volume is indeed related to the volume of blood ejected by the ventricle, it is not equivalent to the cardiac output, which is the total volume of blood pumped by the heart per minute.

**Clinical Pearl / High-Yield Fact**
The Frank-Starling law of the heart highlights the importance of maintaining adequate preload to ensure optimal stroke volume and cardiac output. This is particularly relevant in clinical scenarios such as heart failure, where managing preload through fluid management and vasodilators can significantly impact patient outcomes.

**Correct Answer:** C.