Which of the Following Is an Example of Downward Mobility

Which of the following is an example of downward mobility?

A) Danisha, who was just fired from his job at Wells Fargo bank.
B) George, who stopped receiving welfare payments after getting hired at a shoe store.
C) Harel, who took a leave of absence to care for his ill parents.
D) Jane, who was raised in a middle-class household and now works at a grocery store full time.