Question

what was one way that the development of agriculture impacted the human population?
there were now too many hunter - foragers for the earth to sustain.
the availability of calories per square kilometer increased.
the roman empire switched to hunting and foraging.
they began breeding plants and animals for the military.

Explanation:

To determine the correct answer, we analyze each option:

• Option 1: Hunter - foragers were not "too many" for the earth to sustain before agriculture; agriculture allowed for more people to be sustained. So this is incorrect.
• Option 2: Agriculture led to the domestication of plants and animals, which increased food production. The number of calories (food energy) per square kilometer of land increased because farming and animal husbandry could produce more food than hunting - foraging in the same area. This is a correct impact of agriculture on human population as more food means the land can support more people.
• Option 3: The Roman Empire was not a hunter - forager society, and the switch to hunting and foraging is not related to the development of agriculture's impact on human population. This is incorrect.
• Option 4: Breeding plants and animals for the military is not a primary way that the development of agriculture impacted the human population. The main impact was on food production and population support. This is incorrect.

Answer:

B. The availability of calories per square kilometer increased.