Which of the following best describes the simple spending multiplier?​ Select one: a. It shows the magnified change in planned aggregate spending that arises from a change in equilibrium output.​ b. It shows the magnified change in equilibrium output demanded that arises from a given initial change in planned aggregate spending.​ c. It shows the magnified change in equilibrium output demanded that arises from a change in income.​ d. ​It shows the magnified change in planned aggregate spending that arises from a change in output. e. It shows the change in planned aggregate spending that arises from a change in real output.