The permeability of the aquifer is ________ if the drawdown is 4m, discharge is 40litres/sec, thickness of confined aquifer is 30m and the radius of the well is 0.1m. The radius of influence is taken as 245m.

• A. 36 m/day
• B. 30 m/day
• C. 26 m/day
• D. 20 m/day