While in College,John and Bethany Each Buy Five Packages of Mac-N-Cheese

Multiple Choice

While in college,John and Bethany each buy five packages of mac-n-cheese per week.After they graduate and have full-time jobs,John buys six packages per week,but Bethany buys only two packages per week.When looking at income elasticity of demand for mac-n-cheese,John's

A) is negative,and Bethany's is positive.
B) is positive,and Bethany's is negative.
C) is zero,and Bethany's approaches infinity.
D) approaches infinity,and Bethany's is zero.