Although allergic reactions are triggered by allergens like pollen and fungi, the actual cause of the symptoms like mucous production and constricted airways is a) the body's immune response. b) the effect of medical treatment. c) the surrounding weather conditions. d) the clogging effect of the allergens.

A) the body's immune response.

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.  

succession returns a disturbed

ecosystem to a more stable state. this is also classified into two (2) types:

primary succession and secondary succession. the primary succession arises when

a new land is transformed and a bare rock has been exposed providing an environment

that can be occupied for the first time. while, secondary succession occurs

when a previously occupied environment was disturbed that kills much of all its

community

explanation: