A large open tank has two holes in the wall. One is a square hole of side L at a depth y from the top and the other is a circular hole of radius R at a depth 4y from the top. When the tank is completely filled with water, the quantities of water flowing out per second from both the hole are the same. Then R is equal to

• A. \[2\pi L\]          
• B. \[\frac{L}{\sqrt{2\pi }}\]
• C. \[L\]                
• D. \[\frac{L}{2\pi }\]