Which of the Following Statements Correctly Describes Promoters in E

Which of the following statements correctly describes promoters in E.coli?

A) A promoter may be present on either side of a gene or in the middle of it.
B) All promoters have the same sequence that is recognized by RNA polymerase holoenzyme.
C) Every promoter has a different sequence,with little or no resemblance to other promoters.
D) Many promoters are similar and resemble a consensus sequence,which has the highest affinity for RNA polymerase holoenzyme.
E) Promoters are not essential for gene transcription,but can increase its rate by two- to three-fold.