[swarnava]

Assertion: Gram -ve bacteria stained by saffranin
Reason: Gram -ve bacteria has LPS.

B option is  correct bcoz lps has rol in endotoxin not in staning....

As you will see in Chapter 4, different kinds of bacteria react
differently to the Gram stain because structural differences in
their cell walls affect the retention or escape of a combination of
crystal violet and iodine, called the crystal violet–iodine (CV–I)
complex. Among other differences, gram-positive bacteria have
a thicker peptidoglycan (disaccharides and amino acids) cell wall
than gram-negative bacteria. In addition, gram-negative bacteria
contain a layer of lipopolysaccharide (lipids and polysaccharides)
as part of their cell wall (see Figure 4.13, page 85). When applied
to both gram-positive and gram-negative cells, crystal violet and
then iodine readily enter the cells. Inside the cells, the crystal violet
and iodine combine to form CV–I. This complex is larger than
the crystal violet molecule that entered the cells, and, because of its
size, it cannot be washed out of the intact peptidoglycan layer of
gram-positive cells by alcohol. Consequently, gram-positive cells
retain the color of the crystal violet dye. In gram-negative cells,
however, the alcohol wash disrupts the outer lipopolysaccharide
layer, and the CV–I complex is washed out through the thin layer
of peptidoglycan. As a result, gram-negative cells are colorless
until counterstained with safranin, after which they are pink. OPTION A IS CORRECT REFER TORTORA MICROBIOLOGY PAGE 69