39) The study of the choices made by individuals is part of the definition of microeconomics. B. positive economics. C. macroeconomics D. normative economics. B. 40) Which of the following results in an increase in the demand for a product? A fall in the price of the product.B. A smaller number of consumers wanting to buy the product. A. An increase in the price of the product. D. An increase in the price of a substitute product. C.

39) The study choices made by individuals is part of the definition of microeconomics. Microeconomics focuses on the behavior of individual consumers and firms, and how they make decisions regarding the allocation of limited resources. It examines the interactions between buyers and sellers in individual markets, and how these interactions affect the supply and demand of goods and services.<br /><br />40) An increase in the demand for a product results in a shift of the demand curve to the right. This shift can be caused by various factors, such as an increase in consumer income, a decrease in the price of a complementary product, or a decrease in the price of a substitute product. In this case, the correct answer is D. An increase in the price of a substitute product. When the price of a substitute product increases, consumers may switch to the original product, leading to an increase in the demand for the original product.