Neurons 4591 and 4592 were just like all the other millions of neurons in the brain's center that are created during the first weeks of pregnancy. But in time Neuron 4591 became part of the brain that controls logic, while Neuron 4592 was in an area of the brain that manages emotion. Which process does this describe?
a. specialization.
b. differentiation.
c. migration.
d. proliferation.