Which of the Following Does Not Differentiate Gram-Positive from Gram-Negative

Which of the following does not differentiate Gram-positive from Gram-negative organisms?

A) Multilayered peptidoglycan versus thin peptidoglycan
B) No membrane outside cell wall versus membrane outside cell wall
C) Presence of polysaccharide versus absence of polysaccharide
D) Rich in exotoxin versus rich in endotoxin
E) After iodine treatment retains crystal violet versus does not retain crystal violet