A study finds that towns near coal mines have higher rates of respiratory illness. Which option, if true, MOST DAMAGES the inference that mining causes the illnesses?

1. Identify what is being asked: this is a **Critical Reasoning Weaken** question. 2. Apply the standard approach for this question type to evaluate each option. 3. The correct answer is **B. These towns are also located in valleys that trap industrial pollution from upstream metal smelters** — it satisfies the conditions of the stem. _Source: GMAC Official 12 Sample Questions (mba.com)_