Small molecules that bind with self-proteins to produce antigenic substances are called reagins antibodies haptens ions

The answer will be haptens because haptens has the ability of combining to carriers that are large enough to produce antibodies. The large carriers are usually the proteins that binds to it after producing antibodies. The antibodies, ions and reagins does not comply in the question above for antibodies focus more in the immunization. The ions are the electrons that produce positive or negative electric charge and the reagins are the ones responsible in allergic reactions.