Answer:
D. innate and adaptive branches of immunity.
Step-by-step explanation:
macrophages function is the phagocytosis of the microbes which is an innate response from immune system. The phagocytosed degraded microbes will then initiate the adaptive response.
Presentation of the degraded microbial antigens activates the adaptive response. Antibodies of the adaptive immunity on the surface of virally infected host cells activate natural killer (NK) cells.