Last Year,Joan Bought 50 Pounds of Hamburger When Her Household's

Multiple Choice

Last year,Joan bought 50 pounds of hamburger when her household's income was $40,000.This year,her household income was only $30,000 and Joan bought 60 pounds of hamburger.All else constant,Joan's income elasticity of demand for hamburger is

A) positive,so Joan considers hamburger to be an inferior good.
B) positive,so Joan considers hamburger to be a normal good and a necessity.
C) negative,so Joan considers hamburger to be an inferior good.
D) negative,so Joan considers hamburger to be a normal good but not a necessity.