Answer:
Option "B. It is a linear function because the y-values increase by an equal difference over equal intervals of x-values" is the correct answer
Explanation:
First of all we have to check the function for linear or exponential.
To check for exponential function, we have to find the factor between y values and x values that is:

So,
For x=1

The function is not an exponential function because the factor between each x-value and y-value is not same.
Now,
Let us find the difference between x-values and y-values
Let

So for x-values

And

As we can see that the y-values increase by an equal difference over equal intervals of x-values so the function is a linear function.
Hence,
Option "B. It is a linear function because the y-values increase by an equal difference over equal intervals of x-values" is the correct answer