What members of the family usually live under one roof in japan?

Traditionally, the Japanese families have lived in the joint family or extended family system. This means that members of the immediate family (mother, father and children) lived under one roof with members of the extended family,  like  grandparents and even distant relatives. The family is called kazoku in Japanese. The Japanese place great  importance to family. However, this trend is slowly diminishing, with numerous nuclear families becoming the norm of the day.

It’s either d or b ! but it might be b