it is the substitution of a descriptive word or phrase for a proper name or of a proper name for a trait associated with the name

Epithets

Explanation:

Epithets are sometimes attached to a person's name or appear in place of his or her name, as what might be described as a glorified nickname or sobriquet. An epithet is linked to its noun by long-established usage.

answer; /// i do believe the correct answer is (c) public education;

we would need to be able to read the passage in question to determine which factor allowed david believe he could defeat goliath. post the passage, and i'd love to out.