Final answer:
Technological advancements such as the invention of the plow, introduction of irrigation systems, and development of metal tools all contributed to the creation of agricultural surpluses in river valley civilizations, which led to increases in population and societal complexity.
Step-by-step explanation:
The technological advancements that contributed to the creation of agricultural surpluses in river valley civilizations include the invention of the plow, the introduction of irrigation systems, and the development of metal tools. Each of these technologies played a significant role in enhancing agricultural productivity.
- The invention of the plow: This innovation allowed for more efficient turning of the soil, making it possible to cultivate larger areas more effectively and to plant seeds at the right depth for optimal growth.
- Irrigation systems: These were crucial in controlling water supply, ensuring that crops received the necessary water to grow even in drier conditions. Early irrigation helped civilizations manage water resources and boost crop yields.
- Development of metal tools: Metal tools, such as bronze-bladed plows, were far more durable and efficient than previous tools. They allowed for deeper plowing of fields, which turned over more earth and made the soil more fertile for growing crops.
Combined, these advancements d) All of the above, led to significant increases in the amount of food that could be produced, which contributed to larger population sizes and the complexity of societies.