As your authors note, processing speed improve significantly between childhood and adolescence. Which of the following physical factors helps explain some of this change?

a. An increase in myelination during adolescence allows nerve impulses to travel more rapidly, and this allows for faster and more efficient processing of information.
b. The growth of the amygdalae and hippocampi are both maximized in early adolescence, which enhances the speed of data processing.
c. Hemispheric specialization, which refers to the combined manner in which both halves of the brain simultaneously deal with information, does not begin until puberty.
d. A thickening of the corpus callosum occurs during puberty, and this allows for neural impulses to be sent simultaneously to all four lobes of the cerebrum. This, in turn, drastically enhances processing speed.

a