Which of the Following Is Not Likely to Have Contributed

Which of the following is not likely to have contributed to the stagnating real wage levels experienced in the 1970s in the U.S.?

A) Higher prices for oil,an input in production,led to a decrease in the demand for labor.
B) The working age population increased and increased the supply of labor in the economy.
C) The labor force participation rate of females increased sharply in the 1970s.
D) The imports of consumer goods from Japan led to a decline in domestic production.