Which structure carries genetic information?

A. Centromere
B. Protein
C. Nucleus
D. Chromosome

D. Chromosome

D. Chromosome

The structure that carries genetic information is D. Chromosome.

To find this answer, let's briefly explain each option:
A. Centromere: A centromere is a region of a chromosome that holds the two sister chromatids together during cell division, but it does not carry the genetic information itself.
B. Protein: Although proteins play a vital role in various cellular processes, they do not carry genetic information.
C. Nucleus: The nucleus is a membrane-bound organelle in eukaryotic cells that contains the cell's genetic material, but it is not the structure itself that carries genetic information.
D. Chromosome: A chromosome is a thread-like structure composed of DNA and proteins that carries the genetic information in the form of genes.

Therefore, the correct answer is D. Chromosome.