The abbreviation BOD stands for Biochemical oxygen demand.

The abbreviation BOD stands for Biochemical oxygen demand.

• A. Biochemical oxygen demand
• B. Biological oxygen density
• C. Bacteria oxygen difference
• D. Basic oxygen demand

Answer: (A)

The main idea here is recognizing what BOD means in water quality. BOD stands for Biochemical Oxygen Demand, which is the amount of oxygen that microorganisms will use to break down biodegradable organic matter in a water sample. This makes BOD a key indicator of how much organic pollution is present and how much oxygen could be depleted in a stream or wastewater discharge, potentially harming aquatic life. A common way it’s used is as BOD5—the oxygen consumed over five days at 20°C. The other phrases don’t fit because they aren’t standard terms in this context. “Biological oxygen density” isn’t a recognized measure, “bacteria oxygen difference” doesn’t describe the oxygen used by microbes to decompose organics, and “basic oxygen demand” uses the wrong descriptor for what BOD measures.

The main idea here is recognizing what BOD means in water quality. BOD stands for Biochemical Oxygen Demand, which is the amount of oxygen that microorganisms will use to break down biodegradable organic matter in a water sample. This makes BOD a key indicator of how much organic pollution is present and how much oxygen could be depleted in a stream or wastewater discharge, potentially harming aquatic life. A common way it’s used is as BOD5—the oxygen consumed over five days at 20°C.

The other phrases don’t fit because they aren’t standard terms in this context. “Biological oxygen density” isn’t a recognized measure, “bacteria oxygen difference” doesn’t describe the oxygen used by microbes to decompose organics, and “basic oxygen demand” uses the wrong descriptor for what BOD measures.