To do a certain work, A and B work onalternate days with B beginning the work onthefirst day. A alone can complete the same work in 24 days.If the work gets completed in $$11\frac{1}{3}$$ days. then B alone can complete $$\frac{7}{9}th$$ part of the original work in:

A

$$4\frac{1}{2}$$ days

B

$$6$$ days

C

$$5\frac{1}{2}$$ days

D

$$4$$ days