Nucleotides are linked to make up DNA. Amino acids are linked to make up DNA. Proteins are linked to make up nucleotides. Nucleic acids are linked to make up proteins.
I gave my students this multiple choice question: In living things, smaller substances are linked to make up larger substances. Which of the following correctly describes a larger substance made by linking smaller substances?

Only one answer is correct among these 4 choices:
- Nucleotides are linked to make up DNA.
- Amino acids are linked to make up DNA.
- Proteins are linked to make up nucleotides.
- Nucleic acids are linked to make up proteins.

Could you tell me which one is correct?

Nucleotides are linked to make up DNA.