Answer:
Because arteries provide the needed blood flow to the brain and neurons.
Step-by-step explanation:
A healthy cardiovascular system plays an important role in the prevention of neurological diseases and disorders. Arteries transport blood along with its nutrients and oxygen to the brain and neurons, and if our arteries are healthy, they do this more efficiently.
The second and fourth options are technically correct, but they don't provide an answer to WHY a healthy cardiovascular system helps prevent neurological problems. Also, the relationship between exercise and breathing is more pulmonary (related to the lungs) than cardiovascular.
The third option is incorrect because systems that are close to each other do not necessarily interact. Besides, the cardiovascular system is closed, which means that it has no way to interact with the spinal cord.
That leaves us with the first option as the correct one.