Answer: c. III only
Step-by-step explanation:
The marginal propensity to consume (mpc) measures the proportion of a consumers income that is spent.
The marginal propensity to save (mps) measures the proportion of a consumers income that is saved.
It is usually assumed that disposable income is either saved or spent, so mps + mpc = 1
The multiplier is measured as : 1 / MPS or 1 / (1-MPC)
the MPC has a positive relationship with the multiplier.