Which of the following steps in preparation of a fully mature eukaryotic mrna occurs within the nucleus?
a. transcription
b. capping
c. splicing
d. polyadenylation
e. all of the above

e. All of the above

Explanation:

The processing of mRNA  to a fully mature eukaryotic mRNA requires addition of a  5' cap (Capping) and 3' poly(A) tail ( polyadenylation) to the ends of the transcript, and removal of any intervening introns by splicing. Once processing is completed, the mRNP, which consists of mRNA and associated  proteins, is ready for export from the nucleus.  

the fossil record provides evidence of a common ancestor to many species.