6. Are the following statements true or false? Explain your reasoning. a. In economic theory, the demand for a good must depend only on income and its own price and not on the prices of other goods. b. If two goods are substitutes, then an increase in the price of one of them will reduce the demand for the other. c. If Karli spends all of her income on two goods, it is impossible for both goods to be inferior. d. If a good is inferior, then an increase in its price will increase the demand for it. e. Ivan spends his entire income on two goods one of which is Giffen. If the price of the Giffen good rises, demand for the other good must fall. f. When the price of a good rises and income remains constant, there is a substitution effect on demand but no income effect. g. Polly spends her entire income on two goods, x1 and x2. If x1 is a Giffen good, then Polly views x1 and x2 as substitutes. (Explain your reasoning carefully.)