**Core Concept:** The cerebral cortex is the outermost layer of the brain and is composed of six layers. The six layers are named from layer I to layer VI. Each layer has a distinct structure and function.

**Why the Correct Answer is Right:** The cerebral cortex is divided into layers for various reasons, including the arrangement of neurons and the presence of specific proteins and neurotransmitters. These layers play a crucial role in various cognitive functions, such as sensory processing, motor control, and higher-order thinking. In the cerebral cortex, layer I is the outermost layer, followed by layers II, III, IV, V, and VI.

**Why Each Wrong Option is Incorrect:**

A. **Incorrect**: Layer I is the outermost layer, not layer II.
B. **Incorrect**: Layer III is not the correct layer number.
C. **Incorrect**: Layer IV is not the correct layer number.
D. **Incorrect**: Layer V is not the correct layer number.

**Clinical Pearl / High-Yield Fact:** The cerebral cortex is essential for various cognitive functions, and its dysfunction can lead to neurological disorders such as seizures, aphasia, and dysphasia. Understanding the structure and function of the cerebral cortex is critical for understanding neurological disorders and treatment strategies.

**Correct Answer:** .