I believe it's "C. When glucose levels are low and lactose is present" I may be wrong.
competition
source: my biology teacher
Answer:
A process that increases quantity over time.
Explanation:
The formula for exponential growth of a variable x at the growth rate r, as time t goes on in discrete intervals (that is, at integer times 0, 1, 2, 3, ...), is:

Exponential growth is a process that increases quantity over time. It occurs when the instantaneous rate of change of a quantity with respect to time is proportional to the quantity itself.