Final answer:
The best therapeutic response is to explore the client's feelings about the incident and encourage the client to discuss it in the next group session, promoting resolution and transparency within the group therapy environment.
Step-by-step explanation:
The best therapeutic response to address the client's concern about another group member lying during a group psychotherapy session would be to explore the client's feelings about being lied to by a member. This approach allows the client to express their feelings and concerns, and provides an opportunity for the social worker to assess the impact of the incident on the client and the group dynamics. If the client seems prepared, the social worker can then encourage them to bring up this incident for discussion in the next group session, boosting transparency and promoting conflict resolution within the group. It is crucial for group therapy to maintain a safe environment where members feel comfortable addressing concerns, and part of this involves helping group members to articulate their issues within the group setting rather than indirectly through the therapist.