Turbidity is measured in mg/L.

Explanation:

- Turbidity is a measure of the clarity or cloudiness of water. It indicates the presence of suspended particles in the water.
- The unit of measurement for turbidity is typically expressed in milligrams per liter (mg/L) or nephelometric turbidity units (NTU).
- Turbidity can be caused by various factors such as sediment, algae, organic matter, or other pollutants present in the water.
- The measurement of turbidity is important in water quality assessment as high turbidity levels can affect the aesthetic quality of water, interfere with disinfection processes, and indicate the potential presence of harmful contaminants.
- Turbidity can be measured using a turbidimeter, which measures the amount of light scattered by the suspended particles in the water.
- The turbidity measurement is then expressed in mg/L, which represents the mass of the suspended particles per liter of water.
- The higher the turbidity value, the cloudier the water and the greater the concentration of suspended particles.
- Turbidity levels can vary depending on the source of water, such as rivers, lakes, or groundwater, and can also be influenced by human activities, such as construction, agriculture, or industrial discharges.
- Regulatory agencies often set turbidity limits for different types of water sources to ensure the water is safe for various uses, such as drinking water, recreational activities, or aquatic habitats.
- Monitoring and controlling turbidity levels is an important aspect of water treatment and management to ensure the delivery of clean and safe water to the users.

In conclusion, turbidity is the correct answer as it is measured in mg/L.