Premise: In the letter to Administrator Whitman, Senators Jeffords and Lieberman asked for an analysis of four different scenarios, requesting that EPA analyze the cost and benefits, including all sectors of the economy and impacts on both the supply and demand side of the equation, of the following multi-pollutant emission control scenarios for the nation's electricity generators.

Hypothesis: An analysis of four different situations was required by the senators.
Relation: entailment