Solution
✅ Correct Option: 4
We need the person to enter through C and always walk next to one of the lakes (without walking along any path more than once).
The path will be C-D-E-F-K-L-M-N-K-J-G-F-C=
300+400+300+200+300+400+300+400+300+200+300+400= 3800.
Hence, the answer is '3800'