In a pinning situation, which of the following conditions allows a fall to occur?

In wrestling, a fall occurs when both scapulae of the opponent are in continuous contact with the mat. This is the definitive condition for achieving a pin. The rule emphasizes that both shoulder blades must remain on the mat simultaneously and without interruption, which signifies that the wrestler is effectively controlled and unable to escape.

The other scenarios, such as one scapula being out of bounds or both scapulae being out of bounds, do not fulfill the requirement for a pin because the proper criteria for a fall is not met. If the scapulae are elevated off the mat, it indicates that the opponent is not pinned and can potentially maneuver or escape. Thus, only when both shoulder blades are firmly grounded can a referee call for the fall, underscoring the importance of maintaining that contact for a successful pin.