**Core Concept**
The Herrington classification is a system used to categorize posturing in patients with severe brain injury, particularly in the context of increased intracranial pressure or brainstem dysfunction. Decerebrate rigidity is one of the posturing patterns that can be observed in these patients.

**Why the Correct Answer is Right**
Decerebrate rigidity is characterized by a specific posture, where the patient's arms are extended in front of them, with the elbows slightly flexed and the wrists extended. The legs are also extended, with the knees slightly flexed and the ankles plantarflexed. This posture results from the loss of inhibitory influence from the cerebral cortex over the brainstem, leading to the activation of the extensor muscles. The correct answer should match one of the typical features of decerebrate rigidity.

**Why Each Wrong Option is Incorrect**
**Option A:** This option might describe a different type of posturing, such as decorticate rigidity, which is characterized by flexion of the elbows and wrists, and extension of the legs.
**Option B:** This option might describe a posture that is not typically associated with decerebrate rigidity, such as a normal or relaxed posture.
**Option C:** This option might describe a posture that is associated with decerebrate rigidity, such as extension of the arms and legs.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the Herrington classification is a useful tool for clinicians to quickly assess the severity of brain injury and guide management decisions. Decerebrate rigidity is a critical sign that indicates a severe brain injury and requires prompt intervention.

**Correct Answer:** C. Extension of the arms and legs is a characteristic feature of decerebrate rigidity.