The correct answer is option 2: meanders. Meanders are large bends in a river`s course, where the water flows in a serpentine pattern. Meanders have the greatest erosive power because of the strong energy and momentum of the water as it flows through the bends. This energy allows the river to erode the outer bank of the meander through processes such as hydraulic action and abrasion. As the outer bank erodes, the inner bank is undercut, leading to the formation of a river cliff. Over time, this erosion can cause the meander to straighten, forming an oxbow lake. While gorges, inter-locking spurs, and V-shaped valleys are all associated with river erosion, they do not have the same erosive power as meanders.