In the given diagram, what is true at point B?

The diagram shows Income on the x-axis and Consumption on the y-axis. The line labeled 'C' is the Consumption Curve. The 45-degree line represents all points where Consumption equals Income ($C = Y$).

Point B is the intersection of the Consumption Curve and the 45-degree line. This means that at point B, the level of Consumption is equal to the level of Income.

The Average Propensity to Consume (APC) is defined as the ratio of total consumption to total income:

Since, at point B, Consumption = Income, we can substitute Income for Consumption in the APC formula:

• A. Slope of Consumption Curve = 0: The consumption curve has a positive slope, representing the Marginal Propensity to Consume (MPC), which is greater than 0. So, A is incorrect.
• B. Average Propensity to Consume = 0: As calculated in Step 3, APC = 1 at point B. So, B is incorrect.
• C. Slope of Saving Curve = 1: The slope of the saving curve is the Marginal Propensity to Save (MPS). Since MPC + MPS = 1, and MPC is typically between 0 and 1, MPS would also be between 0 and 1 (not 1, unless MPC = 0). So, C is incorrect.
• D. Average Propensity to Consume = 1: This matches our calculation in Step 3.

Therefore, at point B, the Average Propensity to Consume is 1.

The final answer is $\boxed{\text{D. Average Propensity to Consume = 1}}$.