three circles of radius' s' are drawn in the first quadrant of the xy plane.the first circle is tangent to both axes,the second is tangent to the first circle and the x axis,and the third is tangent to the first circle and the y axis . a circle of radius rs is tangent to both axes and to the second and the third circle.

then the value of ( r / s) is

a)5 b)9 c)6 d) 10