Why Is the Cerebral Cortex Folded in So Many Convolutions

Why is the cerebral cortex folded in so many convolutions?

A) During prenatal development, the neural tube continues to fold over and over on itself, creating a hollow, convoluted structure.
B) The cerebral cortex is very thick, so the folds allow for blood and other fluids to penetrate to the inside of the brain.
C) The many folds allow a greater amount of surface area to fit within the skull.
D) The electrical impulses of the neurons burn away sections of the brain as they start to make their connections, making the brain look like it has folds.