The Figure Given Below Represents the Macroeconomic Equilibrium in the Aggregate

The figure given below represents the macroeconomic equilibrium in the aggregate income and aggregate expenditure framework. Assume that MPI is equal to zero.
Figure 10.4
In the figure:
C: Consumption
I₁ and I₂: Investment
G: Government Spending
X: Exports
-In Figure 10.4, calculate the marginal propensity to consume.

A) 0.67
B) 0.50
C) 0.25
D) 0.33
E) 4