circles having their centers on the x-axis has a y-component or coordinate equal to zero. In this case, with the standard equation of the circle equal to (x-h)^2 + (y-k)^2 = r^2, the one that fits the description of the problem is B.(x - 0)2 + (y - 0)2 = 25 and C.(x - 4)2 + (y - 0)2 = 22