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 holes are the same. Then, R is equal to
A. `L/sqrt(2r)`
B. `2piL`
C. `sqrt(2/r).L`
D. `L/(2pi)`
