You are presented with the question "_ are needed to maintain energy levels " and the following answer choices: 
- Ligaments
 - follicles
 - hydration
 - environment
 - glucose
 - pores
 - exercise
 - Arteries

Now knowing that arteries generally carry oxygen-rich blood and energy levels can plummet due to lack of oxygen-rich red blood cells, choose the best answer.


 

        Arteries 