If a tank holds 4200 gallons of water, which drains from the bottom of the tank in 42 minutes, then Torricelli's Law gives the volume $V$ of water remaining in the tank after $t$ minutes as $$V=4200 \left(1-\frac{t}{42}\right)^2, \qquad 0\leq t\leq 42.$$ Find the rate at which the water is draining from the tank after:

(A) 4 minutes $\rightarrow$ Rate of change =

(B) 13 minutes $\rightarrow$ Rate of change =

(C) 22 minutes $\rightarrow$ Rate of change =