The area marked by A in the figure is the cerebral cortex/cerebral mantle.
Step-by-step explanation:
The cerebral cortex is known as the surface of the brain. It is the outer layer of the cerebrum dividing it into two hemispheres. There a numerous peaks and grooves in this layer called as gyri and sulci.
The cerebral cortex is the largest point of neural intergration in the central nervous system. It is essential for the actions like "attention, perception, awareness, thought, memory, language, and consciousness".