Final answer:
For someone in their early 80s like Bernard, the longest-lasting relationship is most likely with a sibling or a lifelong friend, as these are relationships that can endure from childhood through to old age.
Step-by-step explanation:
If Bernard, who is in his early 80s, is like most people, the longest-lasting relationship in his life is likely with a sibling or a lifelong friend. This is because, as individuals age, they encounter numerous changes in their social environments, such as the passing of their parents and possibly their spouse, as well as the moving away or passing of old friends. However, siblings often continue the role of being part of one's life from childhood well into old age, making that relationship very enduring and significant. Lifelong friends are also a crucial source of emotional support and shared history that help shape an individual's life narrative. Hence, the social connections with siblings or lifelong friends often become the most long-lasting relationships for many elderly individuals like Bernard.