Juliet's words contribute to the rising action of the play by demonstrating her strong desire to marry Romeo. Specifically, she expresses her readiness to commit to him, saying, "If that thy bent of love be honourable, / Thy purpose marriage." This declaration sets the stage for the ensuing events and conflicts, as their love faces obstacles due to their feuding families. Therefore, the correct response is:
They show that Juliet is planning to marry Romeo.