An unconfined aquifer of porosity 35%, permeability 40 m / day, and specific yield of 0.15 has an area of 100 km. If the water table falls uniformly throughout the aquifer area by 0.2 m during a drought, the volume of water lost from storage is 1. 1.5 Mm 2. 3.0 Mm 3. 7.0 Mm 4. 8.0 Mm