For solving this problem we must use a calculator or software that allows us to do an exponential regression.
Using a calculator, for example, we introduce the values of x and y and then we adjust an exponential function of the form:

Where A and k are the parameters to adjust. So solving with a calculator or software we get to this table of data the following result:

Now, taking into account that we can rewrite the function above in the following form:

We see that the adjustment is approximately:

So the correct answer is: C. y = 6.61 × 1.55^x