To do a certain work, the ratio of the efficiencies of A and B is 5 : 11. Working together, they can do the same work in $$27\frac{1}{2}$$ days. A and B work together for 20 days. C alone completes the remaining work in 18 days. C alone can do 75% of the original work in:

A

$$56\frac{1}{2}$$ days

B

35 days

C

33 days

D

$$49\frac{1}{2}$$ days