A Right Conical Circular Vessel Is Being Filled with Green $100 \pi$

A right conical circular vessel is being filled with green industrial waste at a rate of 200 cubic meters per second. How fast is the level rising after $100 \pi$ cubic meters have been poured in (The cone has height 75 m and radius 45 m at its brim. The volume of a cone of height h and cross-sectional radius r at its brim is given by $V = \frac { 1 } { 3 } \pi r ^ { 2 } h$ .) Round your answer to the one decimal place.

A) $1.2 \frac { \mathrm { m } } { \mathrm { s } }$
B) $6.0 \frac { \mathrm { m } } { \mathrm { s } }$
C) $0.4 \frac { \mathrm { m } } { \mathrm { s } }$
D) $6.3 \frac { \mathrm { m } } { \mathrm { s } }$
E) $2.0 \frac { \mathrm { m } } { \mathrm { s } }$