Boussinesq's equation for ascertaining unit pressure at a depth H on sewers due to traffic loads, is

• A. <img src="/_files/images/civil-engineering/waste-water-engineering/184-9.71-1.png">
• B. <img src="/_files/images/civil-engineering/waste-water-engineering/184-9.71-2.png">
• C. <img src="/_files/images/civil-engineering/waste-water-engineering/184-9.71-3.png">
• D. <img src="/_files/images/civil-engineering/waste-water-engineering/184-9.71-4.png">
• E. none of these.