**Core Concept**
The Glasgow Coma Scale (GCS) is a neurological scale used to assess the level of consciousness in a patient. It is a widely used tool in clinical settings to evaluate the severity of brain injury or disease. The GCS assesses three components: eye opening, verbal response, and motor response.

**Why the Correct Answer is Right**
The GCS has a total score range of 3 to 15. A higher score indicates a better neurological status, while a lower score suggests a more severe brain injury. The maximum score of 15 is achieved when a patient opens their eyes spontaneously, responds to verbal commands, and has a normal motor response. The minimum score of 3 is achieved when a patient does not open their eyes, makes no sounds, and has no motor response.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct minimum or maximum score.
**Option B:** This option is incorrect because it does not accurately represent the minimum or maximum score of the GCS.
**Option C:** This option is incorrect because it does not correspond to the correct minimum or maximum score of the GCS.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the GCS is a dynamic scale, and scores can change over time as a patient's condition improves or deteriorates. A patient's GCS score can be used to guide treatment decisions and predict outcomes.

**Correct Answer: D. 3-15**