What is the purpose of a metaphor in a written work?

a. it gives human qualities to nonhuman things to create drama.

b. it equates one thing with another to clarify an idea.

c. it repeats similar structures to keep the reader on track.

d. it reuses words or phrases to emphasize a point?

B.

Explanation:

A metaphor is a rhetorical device used in the writing to make comparison between two unrelated things, but possessing  same characteristics.

For example, the most famous metaphor of Shakespeare from his play "As you Like It", "All the world's a stage". In this metaphor, Shakespeare is comparing two unlike things, "world" and "stage", and by this comparison he is trying to tell that the happenings of the world is like a scripted performance that's done on a stage. And all people of this world are mere players in it.  

So, the purpose of a metaphor is to use a concept that's understandable (which is a second subject) and to use this second subject to help understand the lesser understandable concept (which is the first subject). With this, I conclude that the correct answer for this question is Option B.

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