I do believe the answer is B
Answer:
Adaptive immune defense system consists of lymphocytes like B-lymphocytes and T- lymphocytes. B-lymphocytes provides humoral immunity while T- lymphocytes provide cell-mediated immunity to the body.
99% of lymphocytes circulate freely in the blood and lymph. B lymphocytes differentiate into plasma B cells and B memory cells when interact with antigen presented by T helper cells.
Then plasma cells secrete antibodies in the circulation which binds to extracellular antigens through antigen-binding site. Then the bounded antigen is recognized by receptors present on phagocytic cells. This receptor binds the Fc region of antigen bounded antibody and destroy the antigen by phagocytosis.
Answer: Option A is correct. They eat consumers which ate plants, which absorb it from soil.
Explanation:
Carnivores get nitrogen from the food they eat or consuming nitrogen from the small insects trapped in plant. They eat consumers which in turn eat plants and absorb nitrogen from the soil.