Question

atoms of what element form the backbone of large, complex molecules such as sugars and fats?
a. oxygen
b. sulfur
c. sodium
d. carbon

Explanation:

Sugars (carbohydrates) and fats (lipids) are organic molecules. Carbon has a unique ability to form four covalent bonds, allowing it to create long chains, rings, and complex structures that serve as the backbone of these large molecules. Oxygen, sulfur, and sodium do not have the structural properties to form the backbone of such complex organic molecules like sugars and fats.

Answer:

D. carbon