The response of bacteria that allows them to be identified as gram-positive or gram- negative is due to
a. the type of dna or rna they contain
b. their ability or lack of ability to fix nitrogen.
c. whether they are aerobic or anaerobic.
d. whether their cell walls have a thin or thick layer of peptidoglycan
e. the rrna sequences they demonstrate.

Option D.

Whether their cell walls have a thin or thick layer of peptidoglycan.

Explanation:

Gram positive bacteria have thick cell wall layer of peptidoglycan and their cells stain purple when subjected to gram staining which is crystal violet. Examples are anthrax bacteria, diphtheria e.t.c.

Gram negative bacteria have thin cell wall layer of peptidoglycan and tend to retain the color when stained with crystal violet or gram staining. Examples are E.coli, pseudomonas aeruginosa e.t.c. Gram staining is important to differentiate between gram positive from gram negative bacteria.

i believe the correct answer is d