Stain is not taken by capsule in gram negative organisms because the capsule consist of -a) Polysaccharidesb) Lipopolysaccharidesc) Lipidsd) Protein
High-Yield Explanation
Capsules are protective walls that surround the cell membranes of gram-positive and gram-negative bacteria.
They are usually composed of simple sugar (polysaccharide) except in Bacillus anthracis it is made up of polypeptide (protein).
Capsule is not visible in gram stained smear as it has little affinity for basic dyes.
Note -
For single option go ahead for option 'a', i.e. polysaccharide because, except for Bacillus anthracis, the capsule of almost all the important bacteria is composed of sugar (polysaccharide).
Don't get confuse with word gram-negative in question because the capsule, whether it is of grain positive or gram negative bacteria, is not visible on gram staining.