If the angles A, B andC of a triangle are in an arithmetic progression andif a, b and c denote the lengths of the sides opposite to A, B andC respectively, then the value of the expression $$\frac{a}{c}\sin 2C+\frac{c}{a}\sin 2A$$ is

A

$$\frac{1}{2}$$

B

$$\frac{\sqrt{3}}{2}$$

C

$$1$$

D

$$\sqrt{3}$$