The production possibilities curve assumes all of the following except
a) opportunity costs are constant.
b) scarcity requires economic choices.
c) production of more defense goods means fewer consumer goods.
d) the shape of the production possibilities curve illustrates the law of increasing cost.

The correct answer is D: the shape of the production possibilities curve illustrates the law of increasing cost.

Explanation:

The production possibilities curve is a graphic in economics that shows the combinations of the maximum quantity of a good or service that a population can produce when it decides to produce lower of other good or service, depending on all factors of production and a given technology state.

There are different cases of it, in one the opportunity cost is always constant, as an increase in the production of a good means the decrease in the production of the other.

It also shows that in the real economy a population can not produce everything so it has to decide whether produces one or another.

And to put in an example, the production of more defense goods means fewer consumer goods.

Therefore that the last option, D, is the one that is wrong, so that one is the correct answer.