I think that the answer is d
Endospore staining is used to stain the spore which reside inside the microorganisms, and unlike the exospores, are not present outside the microbial cells. The endospore stain penetrates the microbial cells, and then stain the endospore.
Functionalism. It is according to the concept 'survival of the fittest'
Answer: Ribose nucleotides and the nitrogenous bases
Explanation: RNA consists of ribose nucleotides (nitrogenous bases appended to a ribose sugar) attached by phosphodiester bonds, forming strands of varying lengths. The nitrogenous bases in RNA are adenine, guanine, cytosine, and uracil, which replaces thymine in DNA.