Solution
In this question you are given that the point with coordinates (−6,−7) is the center of circle C, the point with coordinates (−6, 5) lies inside circle C, and the point with coordinates (8,−7) lies outside circle C, so you could draw the following figure.
From the figure, you can see that the distance between (−6,−7) and (−6, 5) is 7+5, or 12, and the radius of C must be greater than 12. You can also see that the distance between (−6,−7) and (8,−7) is 6+8, or 14, and the radius of C must be less than 14. Therefore, since the radius is an integer greater than 12 and less than 14, it must be 13.
The correct answer is \(13.\)