Which of the following statements regarding rna polymerase ii, the enzyme that synthesizes mrna in eukaryotic cells, is true?
a. rna polymerase ii converts between an active form that binds to a promoter and an inactive form that cannot bind to a promoter.
b. rna polymerase ii can bind to a promoter region and initiate transcription either alone or in conjunction with transcription factors.
c. rna polymerase ii requires other transcription factors in order to bind to a promoter site.
d. rna polymerase ii is blocked from initiating transcription when transcription factors bind to a promoter region.