X and Y can complete a certain work in 16 days and 24 days, respectively. They work together for 4 days. Z alone completes the remaining work in $$10\frac{1}{2}$$ days. Y and Z together can complete $$\frac{7}{8}$$th part of the same work in:

A

10 days

B

8 days

C

9 days

D

12 days