A(t) gives the amount of water, in liters, in a storage tank t minutes after a valve is opened. Suppose A′(5)=3. Which of the following statements best interprets A′(5)=3 in this context?
a) Three minutes after the valve is opened, the volume of water in the tank is increasing at a rate of 5 liters per minute.
b) Five minutes after the valve is opened, the volume of water in the tank is increasing at a rate of 15 liters per minute.
c) Five minutes after the valve is opened, the volume of water in the tank is increasing at a rate of 3 liters per minute.
d) The average rate at which water entered the tank during the first 5 minutes is 3 liters per minute.