Biology

The correct definition of a polymer is: C.Long, chain-like molecule made of repeating units.

Explanation:

A polymer is a large molecule (macromolecule) composed of many smaller units called monomers, which are covalently bonded together in a repeating pattern. These monomers can be simple molecules, but when linked together, they form a long, chain-like structure.

Why the other options are incorrect:

A.Circular molecule made with many repeating units: This could describe a cyclic polymer, but generally, polymers are linear or branched, not necessarily circular.