CD4 and CD8 Are

Multiple Choice

CD4 and CD8 are

A) proteins secreted by antigen-presenting cells.
B) receptors present on the surface of natural killer (NK) cells.
C) T-independent antigens.
D) molecules present on the surface of T cells where they interact with MHC molecules.
E) molecules on the surface of antigen-presenting cells where they enhance B cell activity.