In Prokaryotes, the Genes for Metabolic Pathways Are ____

In prokaryotes, the genes for metabolic pathways are ____. ​

A) always expressed for early steps in the pathway, but generally not expressed for later steps in the pathway
B) always expressed so the bacteria can respond to rapidly to changing conditions
C) turned on and off as conditions change
D) always independently regulated
E) generally expressed at low levels, but expressed at high levels when conditions warrant