How are simple carbohydrates able to form larger macromolecules?

A. Organic compounds chemically combine using carbon, hydrogen, and oxygen atoms.
B. Organic compounds chemically combine with inorganic compounds to form large macromolecules.
C. Larger macromolecules first break down into smaller macromolecules and combine during the reaction.
D. The hydrogen in the smaller macromolecules combine to form larger macromolecules.