When an antigen attacks the body, it activates adaptive immunity. This adaptive immunity produces a strong response when it encounters the same antigen for the second time. Which feature of adaptive immunity is essential for this kind of response? A. the ability to remember the antigen it encounters B. the ability to distinguish between self and nonself antigens C. the ability to produce nonspecific antibodies against the foreign antigen D. the ability to secrete lysozymes against pathogenic antigens