Which of the following describes the nature of organic compounds?

Organic compounds are primarily characterized by their composition, which typically includes carbon and hydrogen. This is a fundamental aspect of organic chemistry, as organic molecules often form the backbone of larger compounds. Carbon's ability to form four covalent bonds allows it to create diverse structures, including chains and rings, which is essential for building complex molecules like carbohydrates, lipids, proteins, and nucleic acids.

While organic compounds can contain other elements, such as oxygen, nitrogen, sulfur, and phosphorus, the presence of both carbon and hydrogen is crucial in defining them as organic. This distinction also sets organic compounds apart from inorganic compounds, which do not predominantly feature carbon-hydrogen bonds.

In contrast, the other options do not accurately describe the nature of organic compounds. Organic compounds are not composed of metals, are not exclusively found in liquid tissues, nor are they only made up of amino acids, as amino acids represent a specific category of organic compounds within the broader class.