According to research on grandparent-grandchildren relationships, what is the most common explanation for a remote relationship between grandparents and their grandchildren?

Physical distance is the correct answer.

Studies have shown that having a close relationship between grandparents and grandchildren is important and can reduce symptoms of depression for both. However, more and more kids have grown up without having much physical or emotional contact with their grandparents. The most common explanation for grandparents and grandchildren to have a remote relationship is the physical distance between them.