The most important mechanism by which gram negative bacilli acquire chloramphenicol resistance is :: (A) Decreased permeability into the bacterial cell, (B) Acquisition of a plasmid encoded for chloramphenicol  acetyl transferase, (C) Lowered affinity of the bacterial ribosome for chloramphenicol, (D) Switching over from ribosomal to mitochondrial protein synthesis
Answer is B. None