Answer: A. They aimed to make it difficult for foreigners (or aliens) to become U.S. citizens.
Explanation: If you lived in the United States in 1798, you would've been one of those foreigners who would be deported, meaning to expel a foreigner or immigrant, from a country or nation. They could this if they think an immigrant is standing in illegal grounds or he or she is facing crimes that he or she possibly committed.