Which of the Following Is a Characteristic or Component of an MHC

Multiple Choice

Which of the following is a characteristic or component of an MHC class II molecule?

A) 1 MHC-encoded polypeptide chain called the heavy chain
B) a non-MHC polypeptide associated non-covalently with another subunit
C) $\beta$ ₂-microglobulin
D) a heterodimer,with both subunits encoded by MHC alleles
E) a heterotrimer,with all three subunits encoded by MHC alleles