In Which of the Following Situations Does Loneliness Occur

In which of the following situations does loneliness occur?

A) When there is a difference between the actual level and the desired level of social contact
B) When there is a difference between the level of social contact that the person biologically needs and what he or she achieves
C) When there is a difference between the level of social contact and one's attachment style
D) All of the answers are correct.