When King Arthur was a boy, he was predicted by Merlin, the great magician that when the boy grows up, he will be able to pull out a magical sword from a stone which no one but him can pull up. The name of the sword is the Excalibur in which afterwards, he will be declared as a King. In this case, the right word is C. predestination
The main idea is more specific than a theme . The theme could be food and the main idea might be that people need to be more careful about what they eat .
Hope that helped
It is Expository I guess.
I’m an army my bias is Taehyung my bias wrecker is Hobi