The correct answer is D, domestication of animals. All other alternatives refer to events that only happened later.
In order to affirm an Agricultural Revolution ocurred, historians have to choose the most important changes and events that determine that from that moment onwards life was different.
The most important thing that supports the idea of an Agricultural Revolution is that humans started to domesticate plants and animals, which made possible for them to settle and stop being nomads.
This lead to the birth of cities and to radically change how those people lived.
July 26,1953 I believe is the answer. Hope it helps.<span />
Answer: They helped him by building the empires in the way that he meant it to be built.
Many of those who helped account for the population growth of cities were immigrants arriving from around the world. A steady stream of people from rural America also migrated to the cities during this period. Between 1880 and 1890, almost 40 percent of the townships in the United States lost population because of migration. <span>uring the final years of the 1800s, industrial cities, with all the problems brought on by rapid population growth and lack of infrastructure to support the growth, occupied a special place in U.S. history. For all the problems, and there were many, the cities promoted a special bond between people and laid the foundation for the multiethnic, multicultural society that we cherish today.
Info from: http://www.loc.gov/teachers/classroommaterials/presentationsandactivities/presentations/timeline/ris...
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