The Economic Concepts That Guide Budgeting Include Marginalism, Opportunity Costs

The economic concepts that guide budgeting include marginalism, opportunity costs, and efficient markets. Efficient markets holds that

A) Expanding an activity will eventually lead to diminishing returns
B) Every activity undertaken necessitates foregoing other alternatives
C) People always seek to maximize their own well-being so unexploited profit opportunities will be short-lived
D) Market failure does not occur.