About 25 Days After a Conception, the Brain of a Baby-To-Be

About 25 days after a conception, the brain of a baby-to-be is a tiny tube. Over time the tube grows longer and folds to form pockets that gradually evolve into structurally
Different parts. Inside the tube, neurons reproduce at an astonishing rate and then
Migrate to various locations to take on their functions. All of this happens regardless
Of the future baby's environmental circumstances. Which one of the following
Concepts best describes the nature of this early brain development?

A) mitosis
B) canalization
C) codominance
D) reflexive action