Final answer:
The Sumerians were the first people to live in cities, notably in Uruk around 3000 BCE, which makes none of the given options correct.
Step-by-step explanation:
The first people to live in cities were the Sumerians, who established one of the first true cities in world history, Uruk, in southern Mesopotamia around 3000 BCE. The growth of this city was underpinned by intensive irrigation agriculture and required a sophisticated level of social organization. Thus, the correct answer to the student's question is None of the above, as the provided options do not include the Sumerians. The Hittites, for instance, were indo-Europeans who emerged in Anatolia much later. The Babylonians, while significant to the history of urban development, rose to prominence after the Sumerians. The Cainites and Hamites were not associated with the first cities.