when this engineered dna sequence is added to e. coli bacteria, will lactose be required for insulin expression? a.No, because in the absence of lactose, Lacl is not expressed and therefore cannot block transcription. b.Yes, because Lacl repressor binds to the operator and blocks transcription when lactose is absent. c.No, because RNA polymerase has a high affinity for Placl and will be able to transcribe even if the Lacl repressor binds to the operator. d.Yes, because lactose is required for RNA polymerase to bind to Placl and express the gene.