The correct answer is C. Complete proteins.
Complete proteins contains all the nine amino acids which are essential.
Essential amino acids are termed as amino acids which cannot be synthesized by organisms so they must be supplied in their diet.
The nine amino acids which cannot be synthesized by human include, lysine, histidine, leucine, isoleucine, tryptophan, methionine, valine, phenylalanine.
There are other amino acids which are found to be conditionally essential in the diet which means that under special pathophysiological condition the synthesis can be limited for example, premature in the infant.