Which of the following is advisable in International Politics?

The correct answer is Option 2 - Countries should discuss contentious issues and find peaceful solutions.

Countries have conflicts and differences with each other. That does not necessarily mean they must go to war to deal with their antagonisms. They can, instead, discuss contentious issues and find peaceful solutions; indeed,
even though this is rarely noticed, most conflicts and differences are resolved without going to war. The role of an international organisation can be important in this context.