A person's wound was exposed to some bacteria and then bacteria growth started to happen at the same place. The wound was later treated with some antibacterial medicine and the rate of bacterial decay () was found to be proportional with the square of the existing number of bacteria at any instance. Which of the following set of graphs correctly represents the 'before' and 'after' situation of the application of the medicine?
[Given: = No. of bacteria, = time, bacterial growth follows st order kinetics.]

- A
(1) Before: rises exponentially from as increases. After: starts high and falls off as increases.
- B
(2) Before: rises exponentially from as increases. After: rises from the origin along an upward-curving (parabolic) graph as increases.
- C
(3) Before: rises from rather than from at . After: rises from the origin along an upward-curving graph as increases.
- D
(4) Before: rises exponentially from as increases. After: increases linearly with .
