This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
The semi essential amino acids is: 
Select and explain. 
A. Arginine, B. Phenylalanine, C. Lysine, D. Tryptophan
A: Arginine
Answer: A: Arginine 
Explanation: Ans. A. ArginineSemi essential amino acids are required by lactating mothers and growing children. They are arginine and histidine.Essential amino acids are those which cannot be produced by the body and a have to be supplemented from outside diet.