For this case we have a function of the form:

Where,
A: initial amount
b: rate of change
t: time in years.
When b> 1 the function grows.
When b <1 the function decreases.
For this case we have the following function:

We observed that:

Therefore, the function decreases with the number of years.
Answer:
B the product of the initial value of the camper and its decay factor raised to the number of years since it was purchased