Choose the correct statements.
P. Tc cells recognize antigen with class I MHC molecules on target cells.
Q. Endogenous antigens are degraded into peptides within the cytosol by proteasomes.
R. Exogenous antigens are internalized and degraded within the acidic endocytic compartments.
S. Presentation of nonpeptide antigens derived from bacteria involves the class I-like CD1 molecules.