The water in the hand pump is hot in winter because water comes out from inside and absorbs heat from the surroundings; option [D]. When water travels through pipes underground, it absorbs heat from the relatively warmer Earth. As a result, when it is pumped out, it feels warmer compared to the colder atmospheric temperature. This phenomenon occurs due to the natural tendency of water to reach thermal equilibrium with its surroundings, where it absorbs heat from the warmer environment.
This process is not influenced by our body’s temperature or the temperature inside the Earth being higher than the atmosphere. Friction generated during pumping might slightly heat the water, but it’s not the primary reason for the water being hot. Instead, the predominant factor is the water’s absorption of heat from the surrounding environment.
Therefore, the correct option is [D]. Water absorbs heat from the surroundings, particularly the warmer Earth, as it travels through underground pipes, resulting in it feeling warmer when pumped out during winter.