Some macromolecules are formed from one or two or small molecular fragments that repeat. a) amino acid b) monomer c) polymer d) string

The macromolecules are formed with B) monomers.

A macromolecule is an exceptionally huge particle, for example, protein, usually made by the polymerization of littler subunits called as monomers. They are normally made out of thousands of iotas or more.

The most well-known macromolecules in organic chemistry are biopolymers (nucleic acids, proteins, and sugars) and enormous non-polymeric particles (for example, lipids and macro cycles). Manufactured macromolecules incorporate normal plastics and engineered filaments just as test materials, for example, carbon nanotubes.

Amino acids are monomers of proteins; polymer refers to the chain which is formed by more than one monomer.

B) monomer

Explanation:

Monomers are small molecules capable of binding with other monomers, resulting in macromolecules (which may also be called polymers). Basically monomers are the raw materials of macromolecules, they are simple molecules, usually organic, which when grouped over and over, can be the same molecules or arranged with molecules of other compounds, form long chains called polymers.