I am not really sure about this type of problem, but a diameter has to cross the midpoint of the circle the dark dot and hit two point on both side of the circle. Yet the line 9.6 is not a diameter since it didn't go through the center, so the diameter has to be longer than 9.6. But x is looking for radius. so divide 9.6 by 2 u get 4.8 but that is not a diameter and the real diameter is longer that mean the radius is longer so the only answer is 5.4
