Approximately One in Every Three $\alpha$ $\beta$ T Cells Expresses Two Different Rearranged TCR

Multiple Choice

Approximately one in every three $\alpha$ : $\beta$ T cells expresses two different rearranged TCR $\alpha$ chain proteins. Yet T cells are still considered to have 'clonal specificity' for recognizing antigen. The reason for asserting that each T cell has a single functional specificity for recognizing antigen is that:

A) Only one of the two TCR $\alpha$ chains expressed by a T cell will pair with its TCR $\beta$ chain.
B) T cells expressing two different TCR $\alpha$ chains will die by apoptosis when they are activated.
C) Only one T-cell receptor expressed by each T cell will recognize peptide presented by self-MHC molecules.
D) The majority of T cells in an individual will never encounter their specific peptide-MHC ligand and so will not be part of an immune response.
E) The majority of T cells are self-reactive and therefore eliminated during their development in the thymus.