Why do athletes eat lots of carbohydrates before a competition

I’d say B

carbohydrates improve athletic performance by delaying fatigue and allowing an athlete to compete at higher levels for longer. nutrients, such as fat or muscle protein, are utilized to make energy

and cellulose is a linear polysaccharide polymer with many glucose monosaccharide units

I’m guessing you’re more alert to yourself or your surroundings if you’re more concentrated