Before we start, let's plot the graph of the hyperbola:
The problem wants the distance across the base of the base, we can see that at y = 0 (base) the "vases" touches x = 2.935. that's the distance between the center of the base and the end of it, looking at the image we can see that basically, it's the distance between the x-intercept, we know that half of the distance is 2.935, then the distance is

Therefore, the correct answer is 5.87 inches, distance between x-intercept