Place the Steps of Bacterial Antigen Processing and Presentation in the Correct

Multiple Choice

Place the steps of bacterial antigen processing and presentation in the correct order.
1) Lysosomal enzymes digest the bacterium into molecular bits.
2) The antigen-MHC complex is displayed on the cell surface.
3) The endocytic vesicle fuses with a lysosome.
4) A bacterium is engulfed by a phagocytic cell.

A) 4-3-1-2
B) 4-3-2-1
C) 3-4-2-1
D) 3-4-2-1.
E) 2-4-3-1