The velocity of flow (v) at the outlet of a syphon of length l, is given by

• A. <img src="/_files/images/civil-engineering/hydraulics/153-7.161-1.png">
• B. <img src="/_files/images/civil-engineering/hydraulics/153-7.161-2.png">
• C. <img src="/_files/images/civil-engineering/hydraulics/153-7.161-3.png">
• D. <img src="/_files/images/civil-engineering/hydraulics/153-7.161-4.png">