Abiotic refers to which of the following?

• A. Nonliving chemical and physical factors, such as rainfall, temperature, wind, and pH.
• B. Living factors in an ecosystem, such as plants, animals, and microbes.
• C. Water color.
• D. Microbial populations.

Answer: (A)

Abiotic refers to nonliving components of an environment. Nonliving chemical and physical factors like rainfall, temperature, wind, and pH shape water chemistry and habitat without involving organisms. The other descriptions describe living factors (plants, animals, microbes) or attributes not defined by nonliving status (water color). So focusing on nonliving aspects best captures what abiotic means in ecology and water surveillance.