Which knot is suitable for tying off a loop around an object?

The correct choice is the bowline knot, which is particularly suitable for tying off a loop around an object. This knot creates a fixed loop at the end of a rope that does not slip or bind under load, making it excellent for various applications such as rescue operations, sailing, and climbing.

The bowline is advantageous because it is easy to tie and untie, even after being subjected to a heavy load. It does not constrict the rope, allowing for easy adjustments. Its structure ensures that the loop remains secure while being able to hold weight without slipping, which is critical in many rigging and rescue scenarios.

While the clove hitch is useful for securing a rope to a post or object, it can slip under heavy loads or when not under constant tension, which does not offer the same level of security as the bowline. The half hitch is often used as a securing knot, but on its own, it does not create a stable loop and can easily come undone. The bent knot, often used in specific scenarios, is less common and not typically associated with forming secure loops.

Thus, for creating a reliable loop around an object, the bowline knot is clearly the best choice, ensuring both security and ease of use.