Which of the following is true if the production possibilities curve is a curved line concave to the origin?
a) Resources are perfectly substitutable between the production of the two goods.
b) It is possible to produce more of both products.
c) Both products are equally capable of satisfying consumer wants.
d) The prices of the two products are the same.
e) As more of one good is produced, more and more of the other good must be given up.