Final answer:
The hydrologic cycle is driven by the energy from the Sun, which causes water to evaporate and form water vapor that eventually falls back to Earth as precipitation due to gravity.
Step-by-step explanation:
The hydrologic cycle, also known as the water cycle, is primarily driven by energy from the Sun. The Sun's heat causes water to evaporate from oceans, lakes, and land, turning it into water vapor in the atmosphere. Upon cooling, the vapor condenses and forms clouds, and then, due to gravity, falls back to Earth as precipitation, which includes forms like rain or snow. Furthermore, gravity guides water on land through various pathways such as sinking into the soil, contributing to subsurface water flow, or traveling to the oceans via streams and rivers. Therefore, the correct answer to what drives the hydrologic cycle is B) energy from the Sun.