The peak in 1945 would correlate to what international issue?

It would be on how to handle and manage the world after the Second World War. After the war the allied powers were divided on how the world would look after and it resulted into conflicts and struggles and even resulted a Cold War between the two world's superpower which is the US and the USSR.

One aspect of life for most enslaved people during the 1800s their education was limited to learning how to read.  

Option D

Explanation:

Although it's not accurate because during some cases slaves were not allowed to children to study and though it was practiced but it wasn't universalized. While on the other hand education for slaves wasn't really even limited to read some of them were not even allowed to read because their masters wanted them to be inferior and dependent because institution of slavery was based upon the helplessness of people and their dependence and being sufficient which made them stay as a slave.