题目选项分析

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?

【选项】The inflation figures were computed on the basis of a representative sample of economic data rather than all the available data.