Those who challenge themselves have less blood vessel disease (allowing better blood flow to the brain), heavier brains, and more neurons.

This statement is true

Explanation:

This statement is true. People who challenge themselves have less blood vessel disease and that is happening because in that way with physical activities and challenges the person is having better blood flow to the brain.

They are having also having more neurons and heavier brains.

she forgets to repeat her message as often as necessary