Suppose Cathy and Lewis work in a bakery making pies and cakes. Suppose it takes Cathy 1.5 hours to make a pie and 1 hour to make a cake, and suppose it takes Lewis 2 hours to make a pie and 1.5 hours to make a cake. What is the opportunity cost to Cathy of making a cake?

A.2/3 of a pie.

B.1.5 pies.

C.1 pie.

D.1.33 pies.

正确答案：2/3 of a pie.