Which statement explains why the two sugar-phosphate chains in a DNA molecule remain the same distance apart?
- AAdenine and thymine are held together by the same number of hydrogen bonds as cytosine and guanine.
- BEach nucleotide molecule is the same size.
- CEach purine base is linked to a pyrimidine base.
- DThe sugar-phosphate strands of the helix are held together by sulfur bridges.