Temperatures in the Pacific Northwest have risen steadily since 1981,

Temperatures in the Pacific Northwest have risen steadily since 1981, averaging 2.07 degrees Fahrenheit warmer north of the 46th parallel than in the previous decade. Precipitation and water-table levels, which have historically maintained a measurable relationship to each other (within a scaled range of two to four points), have varied drastically from 1987 to 1991, sometimes deviating as much as six points in fewer than eight months. Reports from Canada indicate a similar median temperature increase, estimated at 2.02 degrees Fahrenheit; research from a 1992 study measures the relational swing in moisture levels at no more than three points.

Of the following, which conclusion is best supported by the evidence above?


A. The higher the temperature of a given area, the more likely it is that the water levels will vary.

B. The variation in temperature in the last decade has been less than the fluctuation of moisture.

C. When temperatures rise north of the 46th parallel, natural water exchange between land and atmosphere must change in the same proportion.

D. Within the last ten years, water table and precipitation levels have varied more in the Pacific Northwest than they have in Canada.

E. Canada will have more stability in weather than will the area of the United States above the 46th parallel.