Final answer:
DNA (c) is the double-helical structure that forms the building blocks of our genetic code.
Step-by-step explanation:
DNA (c) is the double-helical structure that forms the building blocks of our genetic code. It consists of two strands of nucleotides that are bonded together at the bases with hydrogen bonds, creating a double helix shape. Each nucleotide is composed of a nitrogenous base, a five-carbon sugar (deoxyribose), and a phosphate group. This structure carries the genetic information for all living organisms.