An Antigen on an Extracellular Bacterium

Multiple Choice

An antigen on an extracellular bacterium

A) is presented after ingestion by an antigen-presenting cell in a class I molecule after binding in the rough endoplasmic reticulum
B) is presented after ingestion by an antigen-presenting cell after the relevant antigenic peptide has been processed into pieces that are 13-18 amino acids long and the class II molecule has lost the invariant chain in the lysosome and has picked up the processed peptide
C) is presented after ingestion by an antigen-presenting cell in a class II molecule after binding in the rough endoplasmic reticulum
D) is presented after ingestion by an antigen-presenting cell after the relevant antigenic peptide has been processed into pieces that are 13-18 amino acids long, and the class I molecule has lost the invariant chain in the lysosome and has picked up the processed peptide