Respuesta :
Answer:
A or D or both
Explanation:
It says, "Nationalism is a strong feeling of support for one's nation. The support can mean to be proud of one's country and to want it to be the richest and most important country in the world. Nationalism caused many problems among European countries in the years before World War I", so it is logic that the Europeans were afraid that other countries would gain more power if they lost and of course they want to super powerful.
It is A or D because they wanted more power and they wanted more supremency