The pressure variation along the radial direction for vortex flow along a horizontal plane is related by

• A. <img src="/_files/images/civil-engineering/hydraulics/159-7.240-1.png">
• B. <img src="/_files/images/civil-engineering/hydraulics/159-7.240-2.png">
• C. <img src="/_files/images/civil-engineering/hydraulics/159-7.240-3.png">
• D. <img src="/_files/images/civil-engineering/hydraulics/159-7.240-4.png">