Transcriptional regulation often involves a regulatory protein that binds to a segment of DNA and a small

Question:

Transcriptional regulation often involves a regulatory protein that binds to a segment of DNA and a small effector molecule that binds to the regulatory protein. Do the following terms apply to a regulatory protein, a segment of DNA, or a small effector molecule?
A. Repressor
B.Inducer
C.Operator site
D.Corepressor
E. Activator
F. Attenuator
G. Inhibitor