For the system in the given figure G varies slightly, the ratio of open loop sensitivity to closed loop sensitivity is

For the system in the given figure G varies slightly, the ratio of ope

1.	For the system in the given figure G varies slightly, the ratio of open loop sensitivity to closed loop sensitivity is
A.	1 : (1 + GH)
B.	1 : (1 + GH)¯¹
C.	1 : (1 - GH)
D.	1 : (1 - GH)¯¹
Answer» C. 1 : (1 - GH)