问题
单项选择题
When household incomes go down and the quantity of a product demanded goes up, the product is:（）
A. an inferior good.
B. a necessity.
C. a luxury good.
答案
参考答案：A
解析：
When household incomes go down and the quantity demanded of a product goes up, the product is an inferior good. Inferior goods include things like bus travel and margarine.