Reign of terror............................................................................i believe
Answer:
Transcontinental railroad
Explanation:
The Three Main Effects of European Imperialism. Due to European Imperialism and many countries arguing over the land they each wanted, tensions were formed between them. Following this, many countries sought alliances between each other to feel secure. This played a big role in the outbreak of the war for many reasons.
It restricted colonial B) trade
I think it is B, I hope it is help.