The correct answer is option 2, Earth. The water cycle, also known as the hydrological cycle, refers to the continuous movement of water on, above, and below the Earth`s surface. It involves processes such as evaporation, condensation, precipitation, and runoff. On Earth, water evaporates from bodies of water, such as oceans and lakes, and from the ground. It then condenses into clouds and eventually falls back to Earth as precipitation, such as rain or snow. This water then flows into rivers, lakes, and other bodies of water, and the cycle repeats.

It is important to note that the other options are incorrect. Option 1, Jupiter, is a gas giant with no solid surface and its atmosphere is composed mainly of hydrogen and helium. Option 3, Mars, has a very thin atmosphere and limited liquid water, so its water cycle is not as active as Earth`s. Option 4, Venus, has a thick atmosphere primarily composed of carbon dioxide, with no liquid water on its surface. Therefore, the water cycle is not available on these planets.