The correct answer is EXTENDED METAPHOR.
Extended metaphor refers to a comparison between two things that are not alike, which continues throughout a series of sentences in a paragraph or in lines of poem. It is also called sustained metaphor and authors usually use it in order to create a clear comparison between two things.
It is by listening and evaluating the speaker's questions and responses. When the speaker asks a question, he is surely making a point to the audience through his responses. By that kind of communication, the speaker should have given his purpose to the audiences.
