Final answer:
Melissa is in the separation phase of role acquisition, symbolically detaching herself from the memories associated with her previous relationship.
Step-by-step explanation:
Melissa is in the separation phase of role acquisition. The separation phase is marked by detachment from one's previous status and the symbolic removal of reminders of that status. Melissa giving away her engagement and wedding rings is an example of symbolically detaching herself from the memories associated with her previous relationship.