The set of policies on the basis of which countries interact with one another is called

A.

constructive engagement policy

B.

socio-economic policy

C.

national policy

D.

foreign policy

Correct answer is D

The set of policies on the basis of which countries interact with one another is called foreign policy.
It could also be defined as the sum total of decision formulated by the government of a country to manipulate the international environment to attain certain national interest or objective.