Which situations described can be modeled by an exponential function?

(This is on USATestPrep btw.) And I can choose more than 1 answer

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. 1,000 grams of radioactive material with a half-life of 6 hours

E. amusement park membership that costs $40 and then just $5 per visit​