You are presented with the question "What happens when oxygenated blood doesn't reach the brain?" and the following answer choices: 
- anemia
 - Dehydration
 - blood flows to the heart
 - increased iron in the brain
 - arteries unclog
 - It decreases
 - a stroke
 - fever

Now knowing that arteries generally carry oxygen-rich blood and most strokes occur when a blood clot blocks an artery that carries oxygenated blood to the brain, choose the best answer.


 

       a stroke  