The correct option is B Cystenine
Cysteine is a nonessential amino acid (protein building block), meaning that cysteine can be made in the human body. Cysteine is one of the few amino acids that contains sulfur . Cysteine is a component of the antioxidant glutathione . The body also uses cysteine to produce taurine , another amino acid.
So, the correct option is "A" (Cystenine).