Oral means "spoken instead of written,by word of mouth." So the most likely answer is C. it's recited from memory. Examples of that would be Greek mythology,folklore,or legends. For the hundreds of years those were mainly passed down by word of mouth, from memory.
1. Mercenary
2. Bastion
3. Bacchanalian
4. Furtive
5. Extradite/extraditing
6. Copious
7. Avarice
