How are the hip and shoulder lines often related in a figure standing on one leg?

Correct answer: Often tilted in opposite directions

The governing idea is weight shift in figure construction. When one leg carries most of the body weight, the pelvis commonly tilts toward the supporting side, while the shoulders respond with a compensating tilt to keep the body balanced. This opposing relationship is characteristic of a relaxed, natural standing pose, though it is not an absolute rule for every action. Thus option C is correct; “always parallel” and “always vertical” are too rigid, and invisible lines cannot describe structure.