Which Method or Methods of Controlling Eukaryotic Gene Expression Is

Which method or methods of controlling eukaryotic gene expression is NOT employed in prokaryotic cells? Select all that apply.

A) controlling how often a gene is transcribed
B) controlling how an RNA transcript is spliced
C) controlling which mRNAs are exported from the nucleus to the cytosol
D) controlling which mRNAs are translated into protein by the ribosomes