A Healthy 45-Year-Old Child-Care Worker Becomes Infected with a Virus $\alpha$

Multiple Choice

A healthy 45-year-old child-care worker becomes infected with a virus and develops a sore throat,cough,and fever.Infected cells in the bronchial mucosa of this patient process virus-encoded proteins through an intracellular pathway and display peptides derived from the protein on the cell surface bound to class I MHC molecules.CD8⁺ T cells migrate to the mucosa and recognize these peptide-MHC complexes.Which of the following components of the TCR actually bind to the viral peptide-MHC complex?

A) Hypermutated regions: 1 in the $\alpha$ chain,2 in the $\beta$ chain
B) Complementarity-determining regions: 3 in the $\alpha$ chain,3 in the $\beta$ chain
C) Hypervariable regions: 2 in the $\alpha$ chain,2 in the $\beta$ chain
D) Congenic regions: 1 in the $\alpha$ chain,1 in the $\beta$ chain
E) One peptide-binding groove formed by the $\alpha$ chain and the $\beta$ ₂-microglobulin chain