Final answer:
The covalent bond that links the two monomers is formed by dehydration synthesis, which involves the removal of a hydroxyl group from one monomer and a hydrogen atom from the other, resulting in the release of a water molecule as a byproduct. Therefore, the correct option is B.
Step-by-step explanation:
In dehydration synthesis, the covalent bond that links the two monomers is formed by the removal of a hydroxyl group (OH) from one monomer and a hydrogen atom (H) from the other at the site of bond formation. This reaction results in the release of a water molecule as a byproduct.