緊急! AL Macro econ lS-LM model

There are three hypothetical economies. They have different sets of IS and LM functions. IS FunctionLM FunctionEconomy A :Y = $1 000 - 500rY = $400 + 500rEconomy B :Y = $1 800 - 200rY = $500 + 500rEconomy C : Y = $2 400Y = $700 + 500r Suppose the central banks of the three economies reduce the money supply by the same amount. The national income will decrease most in ______ and least in ______. A. Economy A, Economy BB. Economy A, Economy CC. Economy B, Economy C D. Economy C, Economy A

答案: B 但我覺得係C, 負的slope唔係負得愈少愈平, 所以economy B最decrease得多咩?