Fact 1: Antibodies are large, Y-shaped proteins that recognize and bind to antigens. Fact 2: Allergic reactions are caused by substances called antigens. Given the two facts above, allergic reactions can be caused by?
Possible answers:
[A]. animals
[B]. smoking pipes
[C]. Sulfur dioxide
[D]. Chemical energy
[E]. fur and fat
[F]. antibodies
[G]. smoking tobacco
[H]. Pesticides
[F].