The pressure in the air space above an oil (sp. gr. 0.8) surface in a tank is 0.1 kg/cm”. The pressure at 2.5 m below the oil surface will be ___________________?

A. 2 meters of water column
B. 3 meters of water column
C. 3.5 meters of water column
D. 4 m of water column
E. none of the above