The rule of the Zagwe Dynasty is the correct answer.
The event that helped give Christianity a permanent place in Ethiopia was the rise of the Zagwe Dynasty. Even though, during colonialism, Europeans were the ones who spread Christianity in Africa, Ethiopia wasn't included in that. The adoption of Christianity in Ethiopia happened via merchants that resulted in the conversion of Frumentius and consequently led him to become the first bishop in Aksum. The Zagwe dynasty kept the cultural traditions of Aksumite state and let Christianity remain as the official religion in that country.
Slavery was justified by saying that it was 'natural' or 'beneficial' and that it was part of gods plan and to interfere was wrong. Also, people thought that slavery taught people how to live their lives if they thought they lacked the ability to. Mainly also because it was legal, however this is not a very good argument because it can be legal but unethical. Abolishing slavery would threaten the structure of society is another good point.
B. The establishment of women's colleges throughout the US
