The Term Launching Phase Refers to a Period of Time

The term launching phase refers to a period of time during which

A) a child who left home to attend college moves back home as an adult due to financial/economic hardships.
B) one child or more has left home,but the younger children in the family continue to live at home.
C) an only child plans to move out but has not begun the process of doing so yet.
D) the youngest child in a multi-children family plans to move out but has not begun the process of doing so yet.