What is the value of $$512 \div 16 + 4 \times \dfrac{5}{2}  of  \left(\dfrac{1}{8}+ \dfrac{1}{3}\right)$$?

A

$$\dfrac{455}{12}$$

B

$$\dfrac{449}{12}$$

C

$$\dfrac{439}{12}$$

D

$$\dfrac{443}{12}$$