A section of a DNA molecule is transcribed to produce an RNA molecule, which is then altered. Which row shows the RNA molecule before modification and after modification?
- Abefore modification: contains exons and introns; after modification: contains exons only
- Bbefore modification: contains exons and introns; after modification: contains introns only
- Cbefore modification: contains exons only; after modification: contains introns only
- Dbefore modification: contains introns only; after modification: contains exons only