Which structure is characteristic of a Petrarchan sonnet?

A Petrarchan sonnet is characterized by its specific structure of an octave and a sestet. The octave, which consists of eight lines, typically presents a problem, situation, or emotional state, while the sestet, made up of six lines, provides a resolution, counterargument, or reflection on the theme introduced in the octave. This division allows for a clear thematic shift or development, which is a hallmark of the Petrarchan form. In contrast, the other answer choices describe structures that do not align with the traditional definition of a Petrarchan sonnet, as they feature different numbers of lines or configurations that do not fit the established form.