Final answer:
Essential amino acids are the 10 amino acids that the human body cannot produce and need to be obtained from food. They are primarily found in proteins from foods such as meat, eggs, dairy products, grains, legumes, nuts, and seeds.
Step-by-step explanation:
Essential amino acids are not vitamins that dissolve in fat, nor are they units of energy produced by protein. Rather, essential amino acids are a group of amino acids that the human body cannot synthesize on its own and hence need to be included in the diet. It's best described by option d). There are 10 essential amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. These are primarily obtained through proteins found in foods, such as meat, eggs, dairy products, and some plant sources like grains, legumes, nuts, and seeds.
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