Final answer:
The dissatisfaction felt by Elizabeth falls into the Differentiating stage of Knapp's model of relationship stages.
Step-by-step explanation:
The dissatisfaction felt by Elizabeth in her relationship with Aaron falls into the Differentiating stage of Knapp's model of relationship stages. This stage is characterized by individuals acknowledging and recognizing their differences and starting to assert their individuality within the relationship. In this stage, partners may experience dissatisfaction as they become more aware of their differing needs and preferences. Elizabeth's dissatisfaction with Aaron's lack of help with cooking and cleaning suggests a growing awareness of their differences in values and expectations regarding household responsibilities.