While Studying the Biochemistry of a Species of Plant Found

While studying the biochemistry of a species of plant found in alpine bogs, a biologist discovers a previously unknown biomolecule composed entirely of carbon, hydrogen and oxygen. The molecule is a polymer composed of many thousands of a single type of subunit, and has a complex branching structure. This new biomolecule could be

A) a carbohydrate involved in energy storage.
B) a protein that functions in structural support.
C) a nucleic acid involved in energy transfer.
D) a glycoprotein involved in communication between cells.
E) a lipid that is an integral component of cell membranes.