What's the relationship between antigens and antibodies

Antigens cause the production of antibodies, and antibodies attack antigens. (D)

Explanation:

From some online research,

1)An antibody is specifically produced in response to an antigen. (Taken from Quizlet)

2)Antibodies bound to antigens on a pathogen's membrane may activate complement proteins to form a membrane attack complex (Taken from a Quizziz)

3)Antigens trigger your immune system to launch an antibody response. This means each antibody wages war against one target antigen. Once antibodies detect antigens, they bind and neutralize them. (Taken from Healthline)

Basically, this means antibodies are formed whenever antigens exist to counter-act it.

ED2021

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

this is a good question! i'll do some research and come back when i have the answer!