How can you increase friction on the descending line to slow your descent?

To increase friction on the descending line and thereby slow your descent, routing the working line through a carabiner below the descender is an effective technique. This method provides additional friction by creating a bend in the line as it makes contact with the carabiner. The added surface area and angle increase resistance against the descent, allowing for better control and a slower, safer descent.

The other methods listed wouldn't achieve the desired increase in friction in the same way. Using a thicker rope may not necessarily increase friction significantly, as it mainly changes the rope's diameter rather than how the rope interacts with the descender and other equipment. Soaking the rope in water might actually reduce friction by making the rope slick and less grippy. Attaching additional weights could inadvertently increase the speed of descent due to the additional force of gravity acting on the extra weight, which is not a safe or effective way to control descent speed.