Write whether the scenario represents a linear function or an exponential function? Explain why.

A water tank is filled at a rate of 2 gallons per minute.
A vine grows 6 inches every week.
A species of fly doubles its population every month during the summer.
A car increases its distance from a garage as it travels at a constant speed of 25 miles per hour.
The value of a popular painting has been increasing by 12% each year for the past 10 years.