Answer:
B. Only the monthly rental cost of apartments in Lowell is changing exponentially.
Explanation:
To identify how the values of the monthly costs of the departments are changing, we must do a test. 
The test consists of taking an element 
 and the element n of the series, and dividing 
 
Then take the element 
 and the element n and divide 

If b = a, then the exponential function of base "b" 
But if b> a, then the rate of change of the function is not exponential 
For example. For the cost of apartments in Beverly 

So, the cost of apartments in Beverly does not increase at an exponential rate. 
We do the same for the cost of the apartments in Lowell. 

The rate is the same, so the prices increase exponentially. 
Finally, the correct answer is option B: B. Only the monthly rental cost of apartments in Lowell is changing exponentially.