The diagram illustrates an antibody molecule with several parts labelled. Which row correctly identifies the parts that make up an antigen-binding site and possess identical amino acid sequences?
- Aform an antigen-binding site: P and Q; have identical amino acid sequences: R and S
- Bform an antigen-binding site: Q and V; have identical amino acid sequences: P and S
- Cform an antigen-binding site: R and S; have identical amino acid sequences: U and V
- Dform an antigen-binding site: U and V; have identical amino acid sequences: Q and R