Which of These Is TRUE of Middle-Class Decline

Which of these is TRUE of middle-class decline?

A) Wages have not kept up with the cost of living and thus have led to middle class decline.
B) Workers are demanding jobs that pay more and,as a result,are unwilling to work in middle class jobs which has caused middle class decline.
C) Most of the middle class were not willing to take government assistance during the Great Recession which caused the numbers of middle class to decline.
D) Middle class decline is a myth-the upper class is declining.