A can lay railway track between two given stations in 18 days and B can do the same job in 10 days. With the help of C, they did the job in 4 days only. Then, C alone can do the job in
11 \( \frac{10}{17} \) days
14 \( \frac{10}{17} \) days
10 \( \frac{10}{17} \) days
19 \( \frac{10}{17} \) days