Which situations described can be modeled by an exponential function? A. car rental for $38 plus $0.40 mile driven
B. bacteria colony of 5,000 triples every 60 minutes
C. city with a population of 20,000 doubles every 8 years.
D. amusement park membership that costs $40 and then just $5 per visit

I did this exact same question on USATestPrep and here's what I answered that I got correct:

B, C and this one isn't an answer choice but the additional answer was: "1,000 grams of radioactive material with a half-life of 6 hours."

Hope this helps! I'm sorry if it doesn't help future people who sees this :/

step-by-step explanation:

the shape,the size and the distance