Question

I think its a I'm just double checking because ragweed cant hurt you but your body dosnt realize that
What happens when a person who is allergic to ragweed encounters ragweed?

A. Ragweed antigens bind to mast cells, which release histamines.

B. Ragweed antibodies attack the immune system.

C. Mast cells release antihistamines into the bloodstream.

D. The cells of the immune system become weakened.

Answer 1

The correct option is A. 
When a person who is allergic to rag weed encounter it, rag weed antigens will bind to the mast cells which stimulate the release of histamine. When histamine is released, it produce a variety of reactions in the body. Histamine also increases the permeability of the capillaries in order to enhance the flow of white blood cells to the site of the infection.