The answer is A. Organisms compete for limited resources. A is wrong because it has nothing to do with reproduction which is natural selection.
The answer is the Phloem. Food=Phloem
DNA stands for Deoxyribonucleic acid which means it is a nucleic acid. RNA stands for Ribonucleicacid. RNA produces proteins
DNA replicates and stores genetic information.
RNA converts the genetic information contained within DNA to a format used to build proteins.
I would have to say the answer is A based off the information above.
Please correct me if I'm wrong.