GMAT Critical Reasoning (CR) | Re: 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 thatthe 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 arepresentative sample of economic data rather than all of the available data.
(B) Last year, Shale oil reserves discovered in the AmericanMidwest brought crude oil prices temporarily below their recent stable annual level of $110