Evaporation is different than precipitation in that:

a. evaporation is a product and precipitation is the process.

b. evaporation is necessary to the water cycle and precipitation is not always necessary.

c. evaporation requires precipitation but precipitation does not require evaporation.

d. evaporation is a process and precipitation is more of an element in that process.

The answer is D.

Evaporation is the process of a liquid's surface changing to a gas. In the water cycle, liquid water evaporates and becomes water vapor.  The water cycle's evaporation process is driven by the sun and influenced by wind, temperature, and the density of the body of water.

Precipitation  unlike evaporation is not a process. Precipitation describes any liquid or solid water that falls to Earth as a result of condensation in the atmosphere. Precipitation includes rain, snow, and hail.

Therefore precipitation is an element in the process of the evaporation.

the first phase of the government’s plan for settlement was building the transcontinental railroad. the railroad provided a way to bring settlers and manufactured goods west and ship their agricultural and mining produce east. the transcontinental railroad was an essential artery for rapid development of the frontier.

the second phase of the government’s plan was a liberal land distribution policy that made it possible for many people to homestead. with these two key elements—transportation and cheap land—the government rapidly achieved its goal of persuading people to move west, settle on farms, and push back the frontier.