What signal should be used when the load needs to move horizontally closer to the crane while maintaining elevation?

The appropriate signal to use when the load needs to move horizontally closer to the crane while maintaining its elevation is to raise the boom and lower the load. This option is correct because raising the boom allows for greater horizontal reach while keeping the load at the desired elevation.

By elevating the boom, the operator can manipulate the angle of the load to achieve a horizontal movement without bringing it closer to the ground. Lowering the load simultaneously helps in maintaining control over its position and ensuring it moves closer to the crane’s center without risking any accidental lowering or unexpected shifts in height.

The other choices do not effectively address the need to maintain elevation while moving horizontally. Simply lowering the load would result in losing elevation rather than keeping it stable while moving. Moving the crane forward may not be necessary if the goal is to maintain the load's height while achieving horizontal movement. Extending the boom could introduce more complexity in handling the load's position and could lead to situations where the load does not effectively approach the crane.

Thus, raising the boom while lowering the load provides a safe and controlled method to reposition the load horizontally.