When All Resources Used in Production Are Not Perfectly Substitutable

Multiple Choice

When all resources used in production are not perfectly substitutable,

A) specialization does not lead to greater production
B) the economy or firm is producing at a point outside of its production possibilities frontier
C) there will be constant opportunity costs
D) the production possibilities frontier will be concave (bowed outward)
E) the economy or firm will only produce one good in equilibrium