the image above shows an inverted U-tube with the open end, O of one limb below the level, W of water in the tank, in order that water should begin to flow from the tank it is is necessary that

• A.The U-tube is completely filled with water and that P should be higher that W
• B.P should be lower than O and W
• C.P should be lower than W and O should reach the botton of the table
• D.The U-tube is completely filled with water and that P should be lower that W
• E.