An essential nutrient<span> is a </span>nutrient<span> that the body cannot synthesize on its own -- or not to an adequate amount -- and must be provided by the </span>diet<span>. These </span>nutrients are necessary<span> for the body to function properly. The six </span>essential nutrients<span> include carbohydrates, protein, fat, vitamins, minerals, and water.</span>
That would be cellular respiration.
I think the answer is B; that’s assuming that the other allele of the heterozygous brown eyed man is coding for blue eyes. If it’s not then my answers wrong. Tell me if you don’t understand or you need a step by step explaination