Which of the following is a biotic factor?

• A. Grass
• B. Water
• C. Temperature
• D. Light

Answer: (A)

Biotic factors are the living parts of an environment, such as plants, animals, fungi, and microbes. Grass is a living plant that grows, reproduces, and interacts with other organisms, so it belongs to the biotic components of an ecosystem. The other options are abiotic factors—nonliving elements that affect organisms: water is a nonliving resource, temperature is a physical condition, and light is energy from the sun. Since grass is living, it is the biotic factor in this context.