A circular disc $$D_1$$ of mass M and radius R has two identical discs $$D_2$$ and $$D_3$$ of the same mass M and radius R attached rigidly at its opposite ends (see figure). The moment of inertia of the system about the axis OO', passing through the centre of $$D_1$$, as shown in the figure, will be

A

$$MR^2$$

B

$$3MR^2$$

C

$$\frac{4}{5}MR^2$$

D

$$\frac{2}{3}MR^2$$