Make a central idea if don't know search up then answer pls

The central  idea is the central,  unifying element of the story, which ties together all of the  other elements of fiction used by the author to tell the story. The central idea can be best described as the dominant  impression or the universal, generic truth found in the story.

Explanation:

it is due to the halo effect as the impression of the boy created earlier.on the mind of the principle affected his decision