Which resources most directly led to the development of early civilizations in river valleys? select all that apply. a. fertile soil b. fresh water c. metal ores d. slaves e. stone

The answer should be fertile soil. River valleys had especially fertile soil because of the nutrients in the water; also, they would flood at certain times in the year which facilitated agriculture. This led to the development of many civilizations around river valleys because of the ability to practice agriculture in those locations.