Explanation:

•The slope of the consumption curve represents how much consumption changes when income changes.
•Marginal Propensity to Consume (MPC) measures the proportion of additional income that is spent on consumption rather than saved.
•It is calculated as: MPC=ΔCΔYMPC = \frac{\Delta C}{\Delta Y}MPC=ΔYΔC where ΔC is the change in consumption and ΔY is the change in income.
•Marginal Propensity to Save (MPS) (Option 4) refers to the proportion of additional income that is saved, not consumed.
•Average Propensity to Consume (APC) and Average Propensity to Save (APS) (Options 1 & 2) are different as they measure total consumption or savings relative to total income, not the slope of the consumption curve.