Laplacian fundamental equation for a non-compressible flow in three dimensions, is

• A. <img src="/_files/images/civil-engineering/soil-mechanics-and-foundation-engineering/35-11.82-1.png">
• B. <img src="/_files/images/civil-engineering/soil-mechanics-and-foundation-engineering/35-11.82-2.png">
• C. <img src="/_files/images/civil-engineering/soil-mechanics-and-foundation-engineering/35-11.82-3.png">
• D. none of these.