HLA II Molecules Play an Important Role in the Immune $CD4^+$

HLA II molecules play an important role in the immune response. One of their functions is

A) To present peptidic epitopes to $CD4^+$ T helper cells
B) To present peptidic epitopes to $CD8^+$ T helper cells
C) To interact with an epitope on the membranes of most nucleated cells
D) To interact with the gene regions: DP, DQ, DR