With an abundance of food and more permanent shelters, people had more time to devote to the development of new technologies. Better farming equipment, such as the ox-driven plow, were invented. The wheel aided humans greatly in transporting goods from one location to another. The loom allowed people to weave cloth and create finer and more comfortable clothing. Tools were created for measuring the passage of time, such as calendars, star charts and sundials. This helped farmers track when the growing season would arrive, and when the best time to plant crops would be. People learned improved farming techniques, such as how to use fertilizers in their fields, and how to better utilize water through irrigation. What is an effect of the new technologies mentioned in the passage above?

A. Groups were able to live in areas with little to no water.
B. People began living in smaller groups.
C. More people became hunters and gatherers.
D. Agricultural inventions led to surplus of food and increase in population.