After Adjusting for Inflation, a Comparison of the Price of Leg

After adjusting for inflation, a comparison of the price of leg warmers reveals that the price of leg warmers was significantly higher in the 1980s than it is today. Which of the following can explain this?

A) Since the 1980s jeans have become preferable to leg warmers, decreasing the demand for leg warmers.
B) New regulation on the importing of leg warmers made abroad decreased the supply of leg warmers to the United States.
C) An increase in the price of cotton used to make leg warmers has led to a decrease in the price of leg warmers today.
D) The expected increase in the price of yarn has led to a decrease in the price of leg warmers today.