Serine, Tyrosine, and Cysteine are non-essential amino acids. Amino acids can be placed in the category of either essential or non-essential. Essential amino acids are those that are essential in the diet. In other words, we cannot create them through our own metabolism. Non-essential amino acids are those which can be produced from other amino acids and substances in the diet and metabolism. During times of need, the metabolism can shift into producing the amino acids that it requires for synthesizing proteins essential for our survival.Hence,option B is correct.