39. Three operators (OR1, OR2, OR3) are located between the PR and PRMpromoters in thegenome of bacteriophage λ. Which of the following are correct regarding these three operators?
(A) OR1 is located within PR, while OR3 is located within PRM.
(B) All three operators can bind to either λ repressor or Cro.
(C) The binding affinity of the three operators to Cro is OR1 ＞ OR2 ＞ OR3.
(D) X repressor at OR1 helps the repressor bind to OR2 by cooperative binding.
(E) Binding of λ repressor to OR3 leads to increase in the λ repressor gene expression.