A hoist can be hung from a wire rope sling without a shackle if which condition is met?

The correct answer reflects a crucial aspect of rigging practices regarding the compatibility of the hook and the sling. When hanging a hoist from a wire rope sling without using a shackle, it is essential that the diameter of the hook is equal to or greater than the diameter of the sling. This requirement ensures that the hook can securely fit over the sling without risking slippage or disconnection under load.

If the hook's diameter is less than the sling's, there is a high risk of the sling disengaging from the hook, especially during lifting operations, which could lead to dangerous situations. A hook that is appropriately sized relative to the sling provides a stable and secure means of attachment, which is critical for maintaining load security and overall safety during hoisting activities.

Other conditions, such as weight limits or varying diameters, do not address the fundamental requirement of compatibility between the hook and the sling, which is why they do not represent safe or effective rigging practices in this situation.