Answer:
Option). the ability to remember the antigen it encounters
Explanation:
The adaptive or acquired immunity is a type of immunity, which develops by the exposure of pathogens during lifetime. Four features of adaptive immunity includes specificity, diversity, memory, and ability to differentiate between self and non-self.
Cells of adaptive immunity (B cells and T cells) are specific for pathogens. Once the antigens or their components are recognized by pathogens, these cells produce effector cells and memory cells.
These are the memory cells that remember the antigens and provide a rapid and more efficient response during subsequent encounters of those antigens.
Thus, the correct answer is first option.
Answer:
water pollution is the correct answer
