GCS max score is –

**Core Concept**
The Glasgow Coma Scale (GCS) is a neurological scale used to assess the conscious state of a person following a traumatic brain injury. It evaluates three components: eye opening, verbal response, and motor response, providing a total score ranging from 3 to 15.

**Why the Correct Answer is Right**
The GCS is a widely accepted and standardized measure to assess the severity of brain injury. The total score is calculated by adding the scores of each component: eye opening (1-4), verbal response (1-5), and motor response (1-6). The correct maximum score is 15, achieved when a patient opens their eyes spontaneously (4), responds to verbal commands (5), and has a normal motor response (6).

**Why Each Wrong Option is Incorrect**
**Option A:** The maximum score of the GCS is not 8, as this would be the sum of the lowest scores for each component.
**Option B:** The maximum score of the GCS is not 12, as this would be the sum of the lowest scores for eye opening and verbal response, but not motor response.
**Option C:** The maximum score of the GCS is not 18, as this would be the sum of the highest scores for each component, but the GCS does not include an additional component.

**Clinical Pearl / High-Yield Fact**
Remember to assess each component of the GCS in a sequential manner to ensure accurate scoring, and be aware that some patients may exhibit focal neurological deficits, which can affect their GCS score.

**Correct Answer: C. 15**