Answer: A) the body's immune response.
Step-by-step explanation:
Pollen and fungi are natural allergens which may get administered in the body as a foreign antigen. In response to these foreign antigens the body generates an immune response by producing antibodies. These antibodies fight against antigens so that they cannot harm the body in any way. Therefore, symptoms of fever, production of mucous and constricted airways are the examples of production of antibodies in order to generate immune response.