The Hershey and Chase experiment concluded the same by labeling the DNA of the parents with phosphorous and found out that the DNA of the offspring also bear phospho- labeled DNA, which established the fact that DNA is the heritable information source. So, your answer is B.
The correct answer is - They supply the energy needed for living processes.
Both the carbon and the nitrogen, are gases that are crucial for the survival of the organisms on the planet. They are mostly used by the producers in the ecosystems, as they need them to manage to perform their cycles, get nutrition, and of course energy. The producers are the basis of the ecosystems, so if they do not have a healthy supply of carbon and nitrogen, the ecosystems on the whole planet will collapse. The carbon and the nitrogen later go from one organism to another as the energy is transferred, and usually end up back into the atmosphere again.
