Answer the following question given this paragraph: 

Proteins are molecules that have many different functions in living things. All proteins are made of monomers called amino acids ( Figure below ) that connect together like beads on a necklace ( Figure below ). There are only 20 common amino acids needed to build proteins. These amino acids form in thousands of different combinations, making about 100,000 or more unique proteins in humans. Proteins can differ in both the number and order of amino acids. It is the number and order of amino acids that determines the shape of the protein, and it is the shape (structure) of the protein that determines the unique function of the protein. Small proteins have just a few hundred amino acids. The largest proteins have more than 25,000 amino acids.


Q: All proteins are made of monomers called what?

 Choices:

- monotides

- aminotides

- peptides

- amino acids

A:
amino acids
