Which of the following is true of the early formation of brain cells?

a. They form at a constant rate throughout the prenatal period.

b. They begin forming slowly, and then the rate increases throughout prenatal development.

c. They form slowly during the prenatal period, and then the rate increases after birth.

d. They form at a constantly increasing rate prenatally and in early childhood.

e. They are overproduced early in the prenatal period, and then the rate decreases and stabilizes.