If a single pipe of length L and diameter D is to be replaced by three pipes of same material, same length and equal diameter d (d < D), to convey the same total discharge under the same head loss, then d and D are related by

• A. <img src="/_files/images/civil-engineering/gate-exam-questions/899-147-1.png">
• B. <img src="/_files/images/civil-engineering/gate-exam-questions/899-147-2.png">
• C. <img src="/_files/images/civil-engineering/gate-exam-questions/899-147-3.png">
• D. <img src="/_files/images/civil-engineering/gate-exam-questions/899-147-4.png">