Labour measurements

Which of the following statements relating to labour measure is not true?

A) The idle time ratio compare the actual idle number of hours with the expected number of idle hour
B) The production Volume Ratio compare expected labour hours with available labour hours
C) The labour efficiency ratio compare expected labour hours with actual labour hours worked
D) The labour Activity (Capacity) Ratio compare with the actual labour hours worked with available labour hours

And sir Kindly explain it’s options thank you ?