Final answer:
The phase where a nurse and client discuss the client's progress is the Working phase of the therapeutic relationship.
Step-by-step explanation:
The phase in the therapeutic relationship described in the question, where a nurse and client are discussing the client's progress toward understanding his behavior under stress, refers to the Working phase. During this phase, the nurse and client actively collaborate to tackle the issues that have been identified in the orientation phase. It involves exploring stressors, developing coping strategies, and implementing changes to behavior or thought processes.