Which of the Following Statements About the Budget Constraint Is

Multiple Choice

Which of the following statements about the budget constraint is true? The slope of the budget constraint is:
(i) the rate at which a consumer can trade one good for another
(ii) equal to the slope of the highest indifference curve
(iii) constant

A) (i) only
B) (i) and (ii)
C) (ii) and (iii)
D) (i) and (iii)