Which of the following statements about messenger RNA is correct?
- AIn eukaryotic cells, mRNA is made by removing exons from the primary RNA transcript.
- BmRNA is a single-stranded polynucleotide containing a different purine base than DNA.
- CmRNA molecules contain ribose sugars joined to phosphate groups by phosphodiester bonds.
- DThe monomers of mRNA contain a phosphate group, deoxyribose sugar and a nitrogenous base.