An individual living thing

• A. Cells
• B. Organ System
• C. Organism
• D. Biosphere

Answer: (C)

A single living being is called an organism. This term describes a complete, individual life form that can carry out all essential life processes, such as metabolism, growth, response to stimuli, and reproduction. An organism can be made of a single cell (unicellular) or many cells (multicellular), but it remains one living unit. A cell is the basic unit of life, but used alone it doesn’t capture the idea of the entire living individual. An organ system is a collection of organs working together inside a multicellular organism, not a standalone living individual. The biosphere is the global sum of all ecosystems and isn’t an individual organism.