One advantage of a multi-hull is:

Choosing greater stability due to a wide beam as the advantage of a multi-hull is accurate because multi-hull vessels, such as catamarans and trimarans, achieve a stable platform by spreading their weight across multiple hulls. This design creates a wider base that greatly enhances stability, especially in rough waters or when the vessel is subjected to lateral forces, such as wind or waves. Because the hulls are spaced apart, multi-hulls are less likely to tip over compared to monohulls, which offers a safer and more comfortable experience for those on board.

While other choices may have some merit in specific contexts, they do not convey the primary notable advantage that ensures both safety and performance in various marine conditions. For instance, less resistance in water can apply to many types of vessels but isn't exclusive or significant to multi-hulls specifically. High power efficiency might relate to different factors, such as design and engine type, rather than the multi-hull configuration itself. Lastly, while some multi-hulls may be easy to transport due to their smaller size relative to their interior space, this aspect doesn't define their performance and stability characteristics like the wide beam does.