On a Graph of a Consumption Function,what Is the Significance

Multiple Choice

On a graph of a consumption function,what is the significance of the 45-degree line?

A) It connects all points where desired consumption equals desired expenditure.
B) It connects all points where desired consumption equals actual disposable income.
C) It shows the slope of the average consumption function,against which we measure other consumption functions.
D) It connects all points where desired consumption equals desired saving.
E) Desired consumption is zero at all points along the 45-degree line.