Answer:
C. is the increase in consumer spending from a $1 increase in disposable income.
Step-by-step explanation:
As the answer explains, the marginal propensity to consume is the change in consumption from one extra dollar of disposable income. For this same reason, the marginal propensity to consume is less than one (a household cannot consume more than it earns unless it borrows).
For example, if a family makes $1 extra, and spends 80 cents of it in consumer goods, the marginal propensity to consume for that family is 0.8.