The equilibrium level of income depends on aggregate demand. Thus, if aggregate demand changes, the equilibrium level of income changes. This can happen in anyone or combination of the following situations:

(A) Change in autonomous consumption.
(B) Change in marginal propensity to consume.
(C) Income.
(D) Change in autonomous investment.

Choose the correct answer from the options given below:

(A), (B) and (D) only

The correct answer is Option (1) → (A), (B) and (D) only

(A) Change in autonomous consumption — True. If people start consuming more or less even when income is zero (autonomous consumption changes), aggregate demand changes, shifting equilibrium income.

(B) Change in marginal propensity to consume (MPC) — True. A higher MPC increases induced consumption, raising aggregate demand and equilibrium income.

(C) Income — Not a cause. Income itself is the result of equilibrium, not a determinant that shifts aggregate demand.

(D) Change in autonomous investment — True. An increase or decrease in investment directly affects aggregate demand, hence changing equilibrium income.