The answer would be:
D. the fulcrum at one end of the lever.
Both second class and third class levers have their fulcrum located at the end of the lever. They differ in the location of the load and effort. For third class levers the effort is in between the load and the fulcrum. For second class levers, the load is in between the effort and fulcrum. You can look at the attached picture as reference.
