Which of the following statements is TRUE regarding living organisms and carbon?

Carbon is essential for the structure of living organisms because it serves as a fundamental building block of life. It is the primary component of macromolecules such as carbohydrates, proteins, lipids, and nucleic acids, all of which are crucial for cellular structure and function. The versatility of carbon lies in its ability to form stable bonds with many elements, particularly hydrogen, oxygen, and nitrogen, allowing it to create complex molecules that are necessary for the diversity of life.

Living organisms primarily obtain carbon from the environment, particularly in the form of carbon dioxide from the atmosphere or organic compounds in their food. This is integral to processes like photosynthesis, where plants convert carbon dioxide into organic material, thus incorporating carbon into their structure. Additionally, when organisms metabolize food, they use the carbon contained within those organic compounds to produce energy and build their own cellular components.

The other statements are incorrect because they misrepresent the role and origin of carbon in living organisms.