Comparing U

Comparing U.S.income inequality in 1980 and 2010 produces a distorted picture for all EXCEPT which of the following reasons?

A) There have been dramatic shifts in the U.S.labor force.
B) It violates the principle of ceteris paribus.
C) A wider gap between years measured produces a more easily perceived trend in income inequality.
D) A surge in in-kind transfers means poorer individuals have greater disposable income.
E) Changes in tax rates alter the wealth composition in the economy.