Last Year, Sefton Purchased 60 Pounds of Potatoes to Feed

Multiple Choice

Last year, Sefton purchased 60 pounds of potatoes to feed his family of five when his household income was $30,000.This year, his household income fell to $20,000 and Sefton purchased 80 pounds of potatoes.All else constant, Sefton's income elasticity of demand for potatoes is

A) negative, so Sefton considers potatoes to be an inferior good.
B) positive, so Sefton considers potatoes to be an inferior good.
C) positive, so Sefton considers potatoes to be a normal good and a necessity.
D) negative, so Sefton considers potatoes to be a normal good.