If the U-Tube of No $20 ^ { \circ } \mathrm { C }$

If the U-tube of No. 4 is rotated about the right leg, what maximum rpm will result in the $20 ^ { \circ } \mathrm { C }$ water being thrown from the tube?

A) 741 rpm
B) 672 rpm
C) 569 rpm
D) 432 rpm