Answer:
B) A herd of lions whose numbers triple every decade.
Explanation:
Situations that can be modeled by exponential functions:
A situation can be modeled by exponential functions when the change is a multiplication or a division, not a sum or subtractions.
In this question:
In option A, C and D the measures are a sum or subtractions, as the rate of change is always the same. So it rests option B as the answer, as tripling is multiplying by 3.