Last Year, Joan Bought 50 Kilograms of Hamburger Mince When

Multiple Choice

Last year, Joan bought 50 kilograms of hamburger mince when the household income was $40 000. This year, the household income was only $30 000 and Joan bought 60 kilograms of hamburger mince. All else being 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 mince to be an inferior good
D) negative, so Joan considers hamburger mince to be a normal good