The correct answer is option D. the adaptive immune system.
Explanation:
The adaptive immune system is the immune system that takes place after the first exposure to a specific antigen either from vaccination or a pathogen. Adaptive responses are of two types: the cell-mediated and humoral immune response, the cell-mediated immune response occurs with the help of T cells, and where is humoral immune response is B cells and antibodies.
Vaccination targets the adaptive immune system as they produce antibodies against the pathogen provided by vaccination.
Thus, the correct answer is option D. the adaptive immune system.
Watershed conservation aims to protect wildlife in the watershed, restore vegetation, keep the watershed environment healthy, and in very dire cases may even have to relocate the watershed to a less polluted area