Final answer:
Every DNA molecule is made up of molecules called nucleotides, which consist of a nitrogenous base, deoxyribose sugar, and a phosphate group, forming the double helix structure through base pairing. Therefore, the correct option is C.
Step-by-step explanation:
Every DNA molecule is composed of units called nucleotides. These nucleotides are the fundamental building blocks of DNA, and they consist of three parts: a nitrogenous base, a five-carbon sugar called deoxyribose, and a phosphate group. In the structure of DNA, nucleotides are linked together to form two long strands that run in opposite (antiparallel) directions. These strands are arranged in a double helix, with each nitrogenous base pairing with its complement (adenine with thymine, and guanine with cytosine) across the strands.
Therefore, the correct answer to the student's question is: Every DNA molecule is made up of molecules called C nucleotides.