ABC is an isosceles right angle triangle. Angle ABC = 90 degree and AB = 12 cm. What is the ra tio of the radius of the circle inscribed in it to the radius of the circle circumscribing triangle ABC ?

A

$$6 - 3\sqrt{2} : 1\sqrt{2}$$

B

$$6 - \sqrt{2} : 3\sqrt{2}$$

C

$$2 - \sqrt{2} : \sqrt{2}$$

D

$$6 - 3\sqrt{2} : 6\sqrt{2}$$