If L, D and f are the length, diameter and coefficient of friction of a pipe, the ratio of the areas of the pipe A and nozzle a, to transmit maximum power, is

• A. <img src="/_files/images/civil-engineering/hydraulics/156-7.200-1.png">
• B. <img src="/_files/images/civil-engineering/hydraulics/156-7.200-2.png">
• C. <img src="/_files/images/civil-engineering/hydraulics/156-7.200-3.png">
• D. <img src="/_files/images/civil-engineering/hydraulics/156-7.200-4.png">