If b(t) represents the number of birds in a bird feeder t minutes after it is filled with seeds, which statement best interprets the equation b'(t) = kt, where k is a constant? There are k birds at the bird feeder t minutes after it is filled with seeds.
The rate of change in the number of birds in a bird feeder t minutes after it is filled with seeds is constant.
The number of birds at the bird feeder t minutes after it is filled with seeds is proportional to the number of minutes.
The rate of change in the rate of change of the number of birds in a bird feeder t minutes after it is filled with seeds is constant.​