I believe the answer is C. It describes the reasons why internment was believed necessary based on research from historians visiting those camps to learn more about what occurred there.
1. Transmission
2. Emissions
3. Permission or Impression
4. Compromised
5. Domains (sorry it's the closest I could think of:()
6. Dismiss
Hope it helps:)
It shows the readers that not all slave-owners was cruel.
The introduction supports by giving readers an understanding of what you are writing about
