The correct response is:
The kinetic energy of the water would be less at the bottom of the drop in the waterfall river A than at the hydroelectric dam river B.
Explanation: In river A (the waterfall), the water falls freely, converting potential energy into kinetic energy as it descends. At the bottom, the kinetic energy is maximized, but some energy is lost due to splashing and turbulence. In river B (the hydroelectric dam), although the potential energy is also significant at the top, the water is directed through turbines, where the energy is more effectively converted into useful work (electricity). As a result, the kinetic energy of the water coming out of the turbine (at the bottom) may be lower than that of the water falling freely in the waterfall due to this energy conversion process.