Final answer:
Covalent bonds are formed between monomers to form a polymer in biology.
Step-by-step explanation:
The correct answer is B. Covalent bonds.
In biology, monomers are small molecules that can bond together to form larger polymers. The bonds between monomers are called covalent bonds. Covalent bonds involve the sharing of electrons between atoms in a molecule. These bonds are strong and stable, which allows for the formation of complex and diverse polymers in biological systems.