You are presented with the question "What are molecules that the immune system recognizes as foreign to the body?" and the following answer choices: 
- Foreign country.
 - Carbohydrates, or proteins.
 - microorganisms
 - Something that causes allergies
 - Molecular structure.
 - Operating system.
 - sub-units of species
 - Organic compounds

Now knowing that antigens are molecules that the immune system recognizes as foreign to the body and an antigen is a molecule of carbohydrate or protein, choose the best answer.


 

  Carbohydrates, or proteins.       