What Are the Functions of the CI Protein

What are the functions of the cI protein?

A) It binds to the operator O_R and prevents expression of cro and cII.
B) It stimulates transcription of its own coding sequence from promoter P_M.
C) It binds to the operator O_L and prevents transcription from promoter P_L.
D) It induces proteases, which leads to the degradation of cII.
E) All of these choices are correct.