Answer: short-run accounting numbers.

**Explanation:** - **Option A (Incorrect):** Basing investment decisions on opportunity costs is the correct approach, as it involves identifying economic alternatives. This is not a capital allocation pitfall. - **Option B (Incorrect):** Decisions based on after-tax cash flows align with capital allocation principles, as they account for tax impacts and avoid errors like omitting or double-counting cash flows. This is not a pitfall. - **Option C (Correct):** A common pitfall is focusing on short-run accounting metrics such as EPS, net income, or ROE. Companies may prioritize these metrics over long-term economic benefits, leading to suboptimal investment choices that do not align with shareholder interests.

Author: LeetQuiz Editorial Team