The Brain of an Adult Is Approximately Four Times Larger

The brain of an adult is approximately four times larger than that of a newborn. What accounts for this tremendous growth?

A) The complexity of networks between neurons increases.
B) The chemical reaction that occurs when myelin begins to dissolve triggers new nerve cells to develop.
C) New neurons form in response to experiences occurring in the first five years of life.
D) Nutritional benefits of breast milk and formula cause an increase in the production of neurons.