Hunter-gathers: people who lived off wild animals and plants.
Farmers: people who lived in a single location, grew plants, and often raised animals.
Nomadic Herders: people who kept groups of domesticated animals and traveled from place to place in search of grass and water
Explanation:
The key word in hunter-gathers, hunter explains that this include people hunting animals.
Farmers are people who need to look after the farm to make sure the plants are growing sufficiently, which means that they have to stay in a single location.
Nomadic means that they move place from place and herder is someone that looks after animals. These link to the the third answer (people who kept groups of domesticated animals and traveled from place to place in search of grass and water).
