Which knot on a rope is used as an anchor knot that creates a fixed loop that won't slip when tied on a bight?

• A. Figure-eight knot
• B. Figure-eight follow through
• C. Overhand knot
• D. Figure-eight on a bight

Answer: (D)

When you need a loop that stays put as an anchor under load, you want a fixed loop created by tying a knot on a bight. The figure-eight on a bight does exactly that: you fold the rope to form a bight and tie a figure-eight around the two strands, producing a loop that remains fixed and does not slip when tension is applied. The knot’s shape creates multiple contact points that grip the rope, so the loop stays in place even as you load it.

This is why it’s preferred for anchor points. Other knots listed aren’t designed to form a stable fixed loop when tied on a bight: a standard figure-eight is simply a stopper that doesn’t give you a reliable fixed loop tied on a folded rope; the figure-eight follow-through is used for tying rope to a harness rather than creating a dedicated fixed anchor loop on a bight; the overhand is a simple stopper knot that can jam and doesn’t provide the same reliable, non-slipping loop under load.