Final answer:
The marginal utility of a commodity is the rate of change of total utility, increases in income shift the budget constraint outward, the most preferred affordable bundle is called the consumer's ordinary demand, decreases in income shift the budget constraint inward.
Step-by-step explanation:
The marginal utility of a commodity is the rate of change of total utility as the quantity of the commodity consumed changes. Therefore, the correct answer for Q1 is A. total utility.
Increases in income shift the budget constraint outward in a parallel manner, enlarging the consumption set and improving choice. Therefore, the correct answer for Q2 is C. budget set.
The most preferred affordable bundle is called the consumer's ordinary demand at the given prices and budget. Therefore, the correct answer for Q3 is A. ordinary demand.
Decreases in income shift the budget constraint inward in a parallel manner, shrinking the consumption set and reducing choice. Therefore, the correct answer for Q4 is A. budget set.