To Maintain Adequate Nutrition, Animals Require Dietary Access to Certain

To maintain adequate nutrition, animals require dietary access to certain amino acids. An amino acid that is NOT "essential" would be best described as one that ________.

A) can be made by the animal's body from other substances
B) is not used by the animal in biosynthesis
C) must be ingested in the diet
D) is not readily absorbed by the gastrointestinal tract
E) is not found in many proteins