How might human activities change to compensate for a decrease in water supplies?
a) humans might build a factory
b) humans might build draining system
c) humans might extract more water from the ground
d) humans behavior might not change because the water cycle

b) humans might build draining system

Explanation:

Human societies require water for various purposes like sanitation, cooking, drinking, washing, bathing, agricultural irrigation, industrial production and for other needs. Due to increase in abundance of the human population worldwide as well as with the increase in requirement. The human population may experience scarcity of water. Due to decrease in water supplies the human population has to take appropriate measure to meet the demand for water. Therefore, humans might build drainage system is the correct option. They can find the water body in their neighboring region so that a proper drainage system can be constructed which can supply necessary amount of water.