Answer:
The correct answer is c. Cell wall
Step-by-step explanation:
Cell wall is important in determining which bacteria are gram-positive and which bacteria are gram-negative bacteria.
A gram-positive bacteria have a cell wall which is made up of a thick peptidoglycan layer while the cell wall of gram-negative bacteria is mainly composed of lipopolysaccharide. A very thin layer of peptidoglycan is present below the lipopolysaccharide layer in gram-negative bacteria.
Therefore according to their cell wall composition gram-positive bacteria stains purple and gram-negative bacteria stains pink in gram staining procedure. So the correct answer is the Cell wall.