Which best describes the body in terms of simple machines?

The knees are inclined planes, and the lower legs hold the loads. The ankles are the fulcrums.
The lower legs are inclined planes, and the knees hold the loads. The ankles are the fulcrums.
The lower legs are levers, and the knees are fulcrums. The ankles hold the loads.
The knees are levers, and the lower legs are fulcrums. The ankles hold the loads.