Bart was a mortuary worker who noticed that there seemed to be a social class difference in what people placed on the graves of departed family members. what bart observed was a class difference in how people manifest the relationship between external objects and the self.

Extended self

Explanation:

When certain objects and people are seen to be a part of us, this is considered to be our extended self. They extend our identify beyond our mind and body alone. Therefore, when something breaks or when someone dies, we feel their loss deeply. What Bart observed was a class difference in how people manifest their relationship between external objects and the external self.

radiant energy is a form of kinetic energy only.(a)

answer; dead end or culdesac;