Brain regions important to memory begin to atrophy as we age. this is best illustrated by the fact that the blood-brain barrier breaks down beginning in the

This is best illustrated by the fact that the blood-brain barrier breaks down begining in the Hippocampus. Deep inside the medial temporal lobe is the region of the brain known as the limbic system which includes the hippocampus, the amygdala, the cingulate gyrus, the thalamus, the hypothalamus, mammillary body; many of which are important to the processing of memory. The Hippocampus is the region of the brain is responsible for learning and memory. The breakdown of the blood brain barrier causes an increase in neurotoxins in the cerebral spinal fluids hence causing progressive degeneration of brain neurons.

The correct answer is b