If D is the diameter of a pipe of length L and f is the coefficient of friction of pipe then diameter of the nozzle d is

• A. <img src="/_files/images/civil-engineering/hydraulics/162-7.278-1.png">
• B. <img src="/_files/images/civil-engineering/hydraulics/162-7.278-2.png">
• C. <img src="/_files/images/civil-engineering/hydraulics/162-7.278-3.png">
• D. none of these.