Last year the price of crude oil was $50 a barrel, but for the current

Last year the price of crude oil was $50 a barrel, but for the current year it has been $110 a barrel. We can conclude that the price of petroleum is on an upward trend, and the price will be higher next year.

Which of the following, if true, most seriously weakens the conclusion above?

A- The crude oil figures on the basis of a representative sample of economic data rather than all of the available data.
B- Last year, Shale oil reserves discovered in the American Midwest brought crude oil prices temporarily below their recent stable annual level of $110 a gallon to form the basis of the blockbuster movie.
C- Increases in Certain government subsidies are tied to the price of crude oil, and at a price of $110 a barrel or above, these subsidies constitute a force causing further hikes in crude oil prices.
D- The $50 a barrel price of crude oil last year represented a 1 year low.
E- Government intervention cannot affect the price of crude oil to any significant degree.