Which of the following lists contains only essential amino acids?

• A. Alanine, glycine, serine, proline, tyrosine, cysteine, glutamine, asparagine, arginine
• B. Leucine, lysine, tryptophan, methionine, phenylalanine, valine, isoleucine, threonine, histidine
• C. Leucine, alanine, glycine, methionine, tyrosine, valine, serine, threonine, histidine
• D. Phenylalanine, tryptophan, cysteine, proline, valine, isoleucine, threonine, lysine, arginine

Answer: (B)