Sanjay and Rohan can complete a work in 8 days and 12 days, respectively. Starting with Sanjay, they work on alternate days. In how many days will the work be completed?

A

$$8\frac{1}{2}$$

B

$$9\frac{1}{2}$$

C

$$9\frac{2}{3}$$

D

$$9\frac{1}{3}$$