In eukaryotes, which set of post-transcriptional processing steps typically modifies a newly synthesized pre-mRNA to produce a mature mRNA ready for export and translation?

• A. Conversion of DNA to RNA by DNA polymerase, followed by replacement of uracil with thymine and addition of ribosomes to the 3′ end
• B. Removal of exons by spliceosome-mediated splicing, addition of a 3′ 7-methylguanosine cap, and addition of a 5′ poly(A) tail
• C. Addition of a 5′ 7-methylguanosine cap, removal of introns by spliceosome-mediated splicing, and addition of a 3′ poly(A) tail
• D. Direct translation of the pre-mRNA into protein in the nucleus without capping, splicing, or polyadenylation

Answer: (C)