Which of these situations can be modeled by an exponential function? A) The declining population of a city if 100 people move away every year.
B) A herd of lions whose numbers triple every decade.
C) The amount of money Grant has saved up if he makes $18.50 an hour.
D) Total distance if we drive 75mph for x hours.

B) A herd of lions whose numbers triple every decade.

Step-by-step 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.