Which of the following organisms is classified as an autotroph?

Autotrophs are organisms that can produce their own food through processes such as photosynthesis or chemosynthesis, using inorganic substances and an external energy source. Plants are a primary example of autotrophs as they utilize sunlight to convert carbon dioxide and water into glucose and oxygen, through the process of photosynthesis. This ability to synthesize their own food distinguishes them from other organisms that rely on consuming organic matter.

In contrast, humans, fungi, and animals are classified as heterotrophs, as they obtain their nutrition by consuming other organisms or organic material rather than producing their own food. This fundamental difference in how they acquire energy and nutrients highlights the unique role that plants play in ecosystems as primary producers.