Banish Claims that a reflection over the x-axis will carry a circle drawn on a coordinate plane to a circle with the same radius but with a different center. He draws four circles on a coordinate plane below.

If you do a reflection on the x-axis, you're taking the points from (x , y) to (x , -y).
The only case where the circle won't change its center it is when the center is located at the x-axis(when y = 0).
From the examples given in the question, only the circle C won't change its center.
The answer would be:
Circle A: Support
Circle B: Support
Circle C: Refute
Circle D: Support