Question

The best definition for foreign policy is how one country chooses to

Answer 1

I believe the answer is: interact with other countries.

In general, countries preference of choosing their foreign policies are divided into two main approach.

The interventionists tend to like to be involved in other countries affair and provide help for those who they considered as 'ally'. The neutralists tend to like to stay away from other countries' affair and focus on their country's own development.

Answer 2

The best definition for foreign policy is how one country chooses to interact with other countries.

All possible types of interaction fall within the domain of foreign policy.