Brent used to think that Trina's hobby of pottery was endearing, as it showed her crafty side. Now he thinks it is stupid and takes up too much of her time. Which stage of relationship dissolution illustrates this shift in Brent's perception of Trina's hobby?

Differentiating.

Explanation:

According to the "Relationship Termination Model" of Mark L. Knapp, there are five stages in relationship dissolution.

Differentiating Circumscribing Stagnation Avoidance Terminating

Brent in the given situation is at first stage of relationship dissolution i. e., "Differentiating".

In this stage, when the partners make progress in their relationship there comes a time when they might start to see the differences between them as annoying.

In the given question, Brent thinks that Trina's hobby of pottery is wastage of time whereas he at first used to think as endearing.

So, the correct answer is Differentiating.