The true statement about chromosomes is: Chromosomes contain DNA.
To clarify the other options:
- Chromosomes are not found in sets of three; they come in pairs (diploid) or single sets (haploid).
- DNA does not contain chromosomes; rather, DNA is packaged into chromosomes.
- The same number of chromosomes does not appear in haploid and body cells; body cells (diploid) have two sets of chromosomes, while haploid cells (like gametes) have one set.