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
Valine is an essential amino acid since it cannot be synthesized by the body. Which of the following describes the side chain of valine? 
Select and explain. 
A. Contains a sulfhydryl group, B. Contains a branched chain hydrocarbon, C. Contains an aromatic ring, D. Doesn't have a side chain
B: Contains a branched chain hydrocarbon
Answer: B: Contains a branched chain hydrocarbon 
Explanation: Valine, along with isoleucine and leucine, are branched chain amino acids. Cysteine contains a sulfhydryl group. Phenylalanine contains an aromatic ring. Glycine doesn't have a side chain.