Answer:
d. the combinations of output and the interest rate where the goods market is in equilibrium.
Step-by-step explanation:
British economist John Hicks was the first to introduce the IS-LM model in 1937, where IS stands for Investment-Savings and LM stands for Liquidity preference-Money supply. It is a Keynesian macroeconomic model that gives the relationship between the market for economic goods (Investment-Savings) and the money market (Liquidity preference-Money supply). The IS-LM model is a graphical representation of Keynesian economic theory.
The IS curve represents the combinations of output and the interest rate where the goods market is in equilibrium. When there's an increase in government spending, the IS curve would shift to the right on the graph.
Also, when there's an increase in the interest rate, it causes investment spending to decrease as the IS curve shifts to the left with respect to economy.