If $$\overrightarrow{A} = ax\hat{i}+by\hat{j}+cz\hat{k}$$ where a, b, c are constants, then $$\int_{}^{} \int_{S} \overrightarrow{A}.d\overrightarrow{S}$$ wher S is the surface of a unit sphere, is

A

$$\frac{4}{3} \pi (a + b + c)^{2}$$

B

$$\frac{4}{3} \pi (a + b + c)$$

C

$$0$$

D

$$\frac{4}{3} \pi (a^{2} + b^{2} + c^{2})$$