Suppose That Irina Is Prepared to Pay a Maximum of $2.40

Multiple Choice

Suppose that Irina is prepared to pay a maximum of $2.40 for her first glass of cranberry juice,but for each subsequent glass she is only prepared to pay 20 cents less than the previous one.
-In which book is the diamond-water paradox first mentioned?

A) Marx's Das Kapital.
B) Keynes's General Theory.
C) Ricardo's Principles of Political Economy and Taxation.
D) Adam Smith's Wealth of Nations.
E) Marshall's Principles of Economics.