Answer :
The correct answer is A. Expansionist.
The type of decision which increases nation's sphere influence is referred to as expansionist.
Expansionist consists of a state and government policies which are involved in economic, military and territorial expansion.
In order to legitimize and justify expansionism we have pan-nationalism, reunification or anarchism.
Some countries exhibit behaviour of expansionist when it has nuclear weapons or if a state ideology for public in non-interference, or state has no democracy.