Coke and Pepsi are perfect substitutes for Mr. Drinker and the slope of his indifferent curves is -1. One day Mr. Drinker brought 2 cans of Coke and 20 cans of Pepsi. (The cans of both drinks are the same size.)

a.Coke is more expensive than Pepsi.

b.Coke and Pepsi cost the same.

c.None of the above.

d.Coke is less expensive than Pepsi.

e.Mr. Drinker prefers Coke to Pepsi.