How can a flat-bottomed load be moved across a smooth floor?

Using rollers to move a flat-bottomed load across a smooth floor is an effective method due to the low friction they provide. Rollers enable easier movement by distributing the weight of the load and allowing it to glide rather than drag across the surface. This method significantly reduces the effort required to move the load, making it practical for heavy or cumbersome items that would otherwise be too difficult to relocate manually.

The other options present methods that are either less efficient or unsuitable for moving a flat-bottomed load across a smooth surface. For instance, using a crane typically involves lifting the load off the ground, which is unnecessary and inefficient for a smooth floor scenario where the load can simply be rolled. Lifting it with manpower could result in physical strain and potential safety risks, especially with heavier loads. Finally, while a forklift can assist with moving loads, it's not the most effective choice when rollers can facilitate the movement with less effort and more stability.