JEE Math Practice Question

Consider three circles: $${C_1}:{x^2} + {y^2} = {r^2}$$ $${C_2}:{(x - 1)^2} + {(y - 1)^2} = {r^2}$$ $${C_3}:{(x - 2)^2} + {(y - 1)^2} = {r^2}$$ If a line L : y = mx + c be a common tangent to C1, C2 and C3 such that C1 and C3 lie on one side of line L while C2 lies on other side, then the value of $$20({r^2} + c)$$ is equal to :

1. A.23
2. B.15
3. C.12
4. D.6