Once a Thymocyte Has Productively Rearranged a β-Chain Gene,which of These

Once a thymocyte has productively rearranged a β-chain gene,which of these event(s) can occur subsequently? (Select all that apply.)

A) β binds to pTα and is expressed on the cell surface with the CD3 complex and ζ chain.
B) Rearrangement of β-,γ-,and δ-chain genes ceases as a result of the suppression of expression of RAG-1 and RAG-2.
C) The pre-T cell proliferates and produces a clone of cells all expressing an identical β chain.
D) Expression of CD34 and CD2 gives rise to double-positive thymocytes.
E) α-,γ-,and δ-chain loci rearrange simultaneously.