This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Essential amino acids are named so: 
Select and explain. 
A. Because they are produced in the body, B. Because they are not produced in the body, C. They are not impoant for life, D. Every food stuff essentially contains them
B: Because they are not produced in the body
Answer: B: Because they are not produced in the body 
Explanation: Essential amino acids are so called not because they are more impoant to life than the others, but because the body does not synthesize them, making it essential to include them in one's diet in order to obtain them. They are Leucine, Arginine, Histidine, Isoleucine, Meyhionine, Phenylalanine, Threonine, Tryptophan, Valine and lysine. Additionally, cysteine (or sulphur-containing amino acids), tyrosine (or aromatic amino acids), histidine and arginine are required by infants and growing children.