I think the answer is going to be the third one
I understand from the question that it's not own lands that the country is taking over, but other, new lands, potentially already occupied by other lands.
This is then imperialism- the will to built an empire (such as the British Empire), that is, have more land under control.
The correct answer is A.
In the period between WWI and WWII, both countries had suffered important economic crisis and had subsequently based their respective strategies for economic recovery on the boost of the industrial sector, which focused on the production of weapons and military equipment. The two countries were ruled by extreme-rightwing fascist goverments with strong nationalistic ideas, who had adopted defense strategies based on an intense militarization of the countries.