What Best Explains the Recent Upward Redistribution of the Gains

What best explains the recent upward redistribution of the gains of economic expansion in Canada?

A) High-income earners work more hours than others.
B) High-income workers make more of their income from investments.
C) Wages are less generous for the middle-class workers.
D) There are too many qualified people relative to the number of highly skilled occupations.
E) Low-income earners are more likely to retire early.