Antigens are molecules that the immune system recognizes as foreign to the body.
Molecules are a group of atoms.
Antigens are a group of atoms that the immune system recognizes as foreign to the body.
what type of antigens does the immune system recognize as foreign to the body?

[a] animals
[b] epidermal
[c] Allergies
[d] negative
[e] dangerous
[f] graptolites
[g] group of atoms
[h] homogenous