In What Ways Do Enhancers and Silencers Involved in Eukaryotic

In what ways do enhancers and silencers involved in eukaryotic transcription differ from prokaryotic regulatory elements?

A) Unlike eukaryotic elements, prokaryotic elements can be in any particular orientation relative to the promoter.
B) Eukaryotic elements can be varying distances from the promoter, prokaryotic elements cannot.
C) Prokaryotic and eukaryotic regulatory elements do not differ: they are the same in location, form and function.
D) Prokaryotic elements can be found within introns, whereas eukaryotic elements cannot.
E) Prokaryotic elements can 'loop', allowing them to bind to promoters. Due to the complexity of eukaryotic chromosomes, looping is not possible.