The correct solution is 2 – the socket is too large for the patient’s residual stump. The prosthetic must be designed to fit the individual's residual limb accurately. This includes considering the length, circumference, and any unique residual limb features or irregularities. "Pistoning" refers to the up-and-down movement or slippage of the residual limb within the prosthetic socket during walking or other activities. If the socket is too big, it becomes loose, creating excessive movement of the residual limb within the socket during weight-bearing activities.