Final answer:
Joining a craft group would be the best intervention for a client who is isolated and wishes to make friends, as it promotes social interaction and helps develop communication skills in a comfortable setting.
Step-by-step explanation:
Based on the presented scenario, the client who is isolated, withdrawn, and expresses a desire to make friends would likely benefit most from joining a craft group. This intervention provides a setting that encourages social interaction in a relaxed and supportive environment, which can be conducive to building friendships. Engaging in a shared activity like crafting can help the client to feel less isolated and can serve as a natural icebreaker for conversations, making it easier to connect with others. Additionally, craft groups often involve teamwork and collaboration, which could help improve the client's social communication skills. This form of intervention aligns well with the concepts found in community psychology practice, where the value of arts-based projects and group activities is recognized for their potential to foster connections and reduce barriers between participants.