The answer would be a.
Biological catalysts are generally proteins (and a group of RNA molecules called ribozymes), but carbohydrates do not play such a role.
The answer is: decreased circulation
Increased flexibility tend to be achieved by implementing stretching exercise. When we stretch, we would improve our blood circulation because the movement help the blood to flow in different type of direction. In the long run, exercises to increase flexibility would have positive benefit for our cardiovascular system.
Answer:
C. Fe2O3 + 2Al → 2Fe + Al2O3
