Earth's cycle moves water from one reservoir to another. this cycling of materials is one of earth's dynamic processes.

a.) tectonic
b.) rock
c.) hydrologic
d.) carbon

Earth's hydrologic cycle moves water from one reservoir to another. This cycling of materials is one of Earth's dynamic processes. 

The hydrologic cycle begins with the evaporation of water from the surface of the ocean. As moist air is lifted, it cools and water vapor condenses to form clouds. Moisture is transported around the globe until it returns to the surface as precipitation.

The correct answer between all the choices given is the third choice or letter C. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.

an angle + its complement = 90 degrees

81 is a composite number.