What type of organisms are known as photoautotrophs?

Photoautotrophs are organisms that produce their own food using sunlight through the process of photosynthesis. This process involves converting light energy into chemical energy, typically in the form of glucose, which they use as a source of energy and as a building block for growth. Photoautotrophs are pivotal in ecosystems as they form the base of the food chain, converting solar energy into a form that can be used by other organisms, including herbivores and carnivores.

In contrast to the other options provided, the other types of organisms either depend on consuming organic material or other organisms or are adapted to extreme environments, which does not pertain to the energy production process characteristic of photoautotrophs. Thus, the defining feature of photoautotrophs is their ability to harness sunlight to synthesize food, clearly establishing the correctness of the response.