**Core Concept**
Whiplash injury is a type of neck strain caused by sudden, forceful back-and-forth movement of the neck, typically resulting from a rear-end automobile collision. This mechanism of injury involves the sudden acceleration and deceleration of the head, leading to strain on the neck muscles and ligaments.

**Why the Correct Answer is Right**
The correct answer is due to the mechanism of injury, which involves the sudden movement of the head and neck. This movement causes the neck muscles and ligaments to stretch and tear, leading to pain, stiffness, and limited range of motion. The acceleration-deceleration mechanism is thought to be responsible for the injury, as it puts excessive stress on the neck structures.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the mechanism of whiplash injury. While a direct blow to the head can cause injury, it is not the primary mechanism of whiplash.
**Option B:** This option is incorrect because it refers to a different type of injury, which is typically caused by a direct blow to the head or a fall. It does not involve the sudden acceleration-deceleration mechanism seen in whiplash.
**Option C:** This option is incorrect because it refers to a different type of injury, which is typically caused by a compression force to the neck. It does not involve the sudden back-and-forth movement of the neck seen in whiplash.

**Clinical Pearl / High-Yield Fact**
A key factor in diagnosing whiplash injury is the patient's history of a sudden, forceful back-and-forth movement of the neck, often resulting from a rear-end automobile collision. This mechanism of injury should be considered in patients presenting with neck pain and stiffness after such an event.

**Correct Answer: B. Soft tissue injury**