Which of the following refers to the major change in a Petrarchan sonnet?

The major change in a Petrarchan sonnet is referred to as the volta. In the structure of a Petrarchan sonnet, which typically consists of an octave followed by a sestet, the volta signifies a pivotal turn or shift in thought or argument. This transition usually occurs between the eighth and ninth lines, where the poet introduces a shift in perspective, tone, or subject matter. This element is essential to the sonnet's overall emotional and intellectual impact, allowing the poet to explore different facets of a theme or idea.

In contrast, a couplet is a two-line stanza, often used in other forms of poetry such as the Shakespearean sonnet, but it does not specifically denote a shift in a Petrarchan sonnet. Quatrains, which are four-line stanzas, are components of both Petrarchan and Shakespearean sonnets, but they don’t indicate a change. An envoi is a brief concluding stanza often used in formats like the sestina and villanelle, rather than specifically addressing the structure and function of a Petrarchan sonnet. Therefore, the volta is distinctly recognized as the moment of change within this specific poetic form.