Let the system of equations : $$2x + 3y + 5z = 9$$, $$7x + 3y - 2z = 8$$, $$12x + 3y - (4 + \lambda)z = 16 - \mu$$, have infinitely many solutions. Then the radius of the circle centred at $$(\lambda, \mu)$$ and touching the line $$4x = 3y$$ is

A

$$\frac{17}{5}$$

B

$$\frac{7}{5}$$

C

7

D

$$\frac{21}{5}$$