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 cells
C) T-independent antigens
D) molecules present on the surface of T cells where they interact with major histocompatibility (MHC) molecules
E) molecules on the surface of antigen-presenting cells where they enhance B-cell activity