39. Last year the rate of inflation was 1.2 percent, but during the current year it has been 4 percent. We can conclude that inflation is on an upward trend and the rate will be still higher next year. Which of the following, if true, most seriously weakens the conclusion above? • (A) The inflation figures were computed on the basis of a representative sample of economic data rather than all of the available data. (B) Last year a dip in oil prices brought inflation temporarily below its recent stable annual level of 4 percent. (C) Increases in the pay of some workers are tied to the level of inflation, and at an inflation rate of 4 percent or above, these pay raises constitute a force causing further inflation. (D) The 1.2 percent rate of inflation last year represented a 10-year low. Government intervention cannot affect the rate of inflation to any significant degree. 请问为什么b是对的,没看明白og 解释,谢谢各位啦~~~ | 
