The Promoters of Positively Controlled Operons Require Activator Proteins, Because

Multiple Choice

The promoters of positively controlled operons require activator proteins, because

A) the promoters have nucleotide sequences that bind RNA polymerase weakly, which are not close matches to the consensus sequence.
B) they are needed to bind to the allosteric site of RNA polymerase.
C) RNA polymerase easily recognizes the consensus sequence.
D) they are required to inactivate the repressor proteins.