QUESTION 21 The utility function u (x, y ) = log (x ) + y generates demand curves such that : Oa. Good y is purchased only if income is very low Ob. Once the income level is such that good x is purchased in positive quantity, any further increase in income is used to buy only good x Oc. Once the income level is such that good y is purchased in positive quantity, any further increase in income is used to buy only good y Od. None of the other proposed answers is correct Oe. The demand for good x does not depend on prices