It is a question raised and answered by the author / speaker.

The author / speaker raises a question and also gives an answer to the question. Hypophora is used to get the audience's attention and make them curious. Often the question is raised at the beginning of a paragraph and answered in the course of that paragraph. Hypophora can also be used, however, to introduce a new area of discussion.

Example:

Why is it better to love than be loved? It is surer. (Sarah Guitry).