**Core Concept**
Fractures are classified based on the mechanism of injury, which can be determined by the type of force applied. The force can be categorized as violent or non-violent. Violent forces are typically high-energy injuries that result in comminuted or segmental fractures.

**Why the Correct Answer is Right**
A comminuted fracture is a type of fracture where the bone breaks into multiple fragments. This type of fracture typically requires a violent force, such as a high-speed motor vehicle collision or a fall from a great height. The violent force causes the bone to shatter into multiple pieces, making it difficult to reduce and stabilize.

**Why Each Wrong Option is Incorrect**
**Option A:** A simple fracture, also known as a linear fracture, is a type of fracture where the bone breaks in one or two places. This type of fracture can be caused by a non-violent force, such as a slip and fall on an outstretched hand.
**Option B:** A stress fracture is a type of fracture that occurs due to repetitive stress or overuse. This type of fracture is typically caused by a non-violent force, such as running or jumping without proper training.
**Option C:** A greenstick fracture is a type of fracture that occurs in children, where the bone bends and partially breaks. This type of fracture is typically caused by a non-violent force, such as a fall on a soft surface.

**Clinical Pearl / High-Yield Fact**
Remember that the mechanism of injury is a critical factor in determining the type of fracture. A violent force is typically associated with high-energy injuries, such as comminuted fractures.

**Correct Answer:** C. Greenstick fractures are typically caused by non-violent forces, such as falls on soft surfaces, and are more common in children.