Which of the following statements defines correctly the efficiency of a machine?
A. the load carried by the machine divided by effort required in carrying the load B. the distance moved by the load divided by the distance moved by the effort C. the useful work done by the machine divided by the total work put into the machine D. the movement of the load divided by the movement of the effort about the same point E. the temperature at the end of the application of the machine divided by the initial temperature
