Two men can complete as much work as 3 women can do in a certain time. Ten men and 6 women can complete a work in 5 days. If 4 men and 9 women work together, then in how many days will they be able to complete the same work?

A

8

B

7

C

$$6\frac{1}{2}$$

D

$$7\frac{1}{2}$$