I'm not sure how exactly you wanted this question to be answered. You're either talking about the symmetry where animals would have two legs or two arms for example and thus producing a pair of each muscle on both sides of the body, or you're refering to the development of agonistic and antaonistic muscles where each of them served a different purpose; either extending or contracting.
Artificial Selection? I'm just guessing
Answer:
B. Carry heredity information
Explanation:
Nucleic acids are one of the four types of biological molecules in nature. The other three being: proteins, carbohydrates, lipids. Nucleic acids consists of Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA).
DNA is a nucleic acid found in the NUCLEUS of eukaryotic cells or nucleoid region of prokaryotic cells where it functions to store or hold genetic information for the cell. On the other hand, RNA functions to carry the stored information in order to be expressed. Hence, according to this question, the nucleic acid functions to carry heredity information.