Which of these statements is completely true about the WT situation above?
A. Gene Z is expressed in the presence of Stimulus A and blocked in the absence of A
B. Gene Z is blocked in the presence of Stimulus A and expressed in the absence of A
C. Gene Z is blocked in the presence of Stimulus A and blocked in the absence of A
D. Gene Z is expressed in the presence of A and expressed in the absence of A
E. None of the above
