Why is it that older adults seem to have declines in their psychomotor speed and their working memories when compared to younger adults?
A. Because they experience a reduction in the ability of the corpus callosum to send messages from one cerebral hemisphere to the other.
B. Because they experience more neuronal death in the diencephalon (the thalamus and hypothalamus), which hinders these cognitive skills.
C. Because they experience a reduction in neurofibrillary tangles, which inhibits the ability of neurons to send messages at a maximally efficient speed.
D. Because they show greater activation of the prefrontal cortex on easier tasks, thus "using up" their brain power before they ascend to more difficult tasks