Foreign invaders have protiens called {pus,antigens,lymph,mucus} which antibodies lock onto to neutralize.

Antibodies bind to antigens on pathogen cell membranes to neutralise them.

Unrestricted populations of organisms experience exponential growth. The correct option among all the options that are given in the question is the first option or option "A". The other choices are incorrect and can be easily avoided. I hope that this is the answer that has come to your great help.