Answer:
Carbohydrates.
Step-by-step explanation:
Biomolecules may be defined as the important chemical molecules that are present in the living organism. Four important bio molecules are carbohydrates, proteins, lipids and nucleic acids.
The carbohydrates contains the carbon, hydrogen and oxygen in its basic structure. The sugars are the monomers of the carbohydrates. The carbohydrate structure consists of carbon, hydrogen and oxygen in a 1:2:1 ratio.
Thus, the correct answer is option (A).