Last Year,Keith Purchased 20 Pounds of Beef When His Income

Multiple Choice

Last year,Keith purchased 20 pounds of beef when his income was $30,000.This year his income is $40,000 and he purchased 40 pounds of beef.Which of the following statements is true?

A) Keith's demand for beef is price inelastic.
B) Beef and income are substitutes.
C) Keith's demand for beef is price elastic.
D) Beef is a normal good.
E) None of the other answers is true.