Biological Oxygen Demand (BOD) is a standard criterion for

1. A. Measuring oxygen levels in blood
2. B. Computing oxygen levels in forest ecosystems
3. C. Pollution assay in aquatic ecosystems
4. D. Assessing oxygen levels in high altitude regions

Answer: C

Explanation

Biological oxygen demand (BOD) is the amount of dissolved oxygen needed (i. e., demanded) by aerobic micro organisms to break down organic material present in a given water sample. A highly polluted water will have a high levels of biological oxygen demand (BOD).