What is the definition of the rhetorical technique of metaphor?

What is the definition of the rhetorical technique of metaphor?

a type of language that creates a contradiction
a type of language that creates a contradiction

a way of speaking or writing that uses imagery to convey an idea
a way of speaking or writing that uses imagery to convey an idea

a figure of speech that suggests a likeness by making a nonliteral comparison of unlike things
a figure of speech that suggests a likeness by making a nonliteral comparison of unlike things

a point-by-point comparison between two things or ideas based on similarities

It's a convoluted question, but all you need to do is look up the meaning of "metaphor." Try using dictionary(dot)com. Then let us know what you choose.