Fact 1: Antigens are molecules that the immune system recognizes as foreign to the body. Fact 2: An antigen is a molecule of carbohydrate or protein. Given the two facts above, what are molecules that the immune system recognizes as foreign to the body?

pick from the following.
1). Foreign country.
2). Carbohydrates, or proteins.
3). microorganisms
4). Something that causes allergies
5). Molecular structure.
6). Operating system.
7). sub-units of species
8). Organic compounds
The answer is:
2).