K' can do `3//4^(th)` of a work in 6 days and 'I can do `2//5^(th)` of the same work in 4 days. How long (in days) will they take, if they work together to finish the work?

Options

A. `4(2)/3`
B. `4(3)/8`
C. `4(1)/4`
D. `4(4)/9`

Answer

D