Answer:
B. Millions
Step-by-step explanation:
Carbon is unique in its ability to form long chains and rings of atoms through covalent bonding, allowing it to form a vast number of different compounds. Carbon is the basis of organic chemistry, which is the study of compounds containing carbon. Organic compounds are essential to life and make up a significant portion of all known compounds, including carbohydrates, lipids, proteins, and nucleic acids. Carbon can also form many inorganic compounds, such as carbon dioxide, carbon monoxide, and carbonates.