You are trying to develop a more effective immunization against rabies. To be double sure that the immune system recognizes your immunization as foreign, you add plastic-aluminum micro-pellets to your immunization mixture. You also add pulverized, purified samples of rabies pathogens in your immunization mixture. You begin trials and discover that your vaccine completely prevents rabies symptoms in any animal treated with your vaccine prior to rabies exposure, and that no animals catch rabies from your vaccine. Select the best explanation for why your immunization treatment is highly effective.
By injecting the pulverized rabies pathogens, you created memory macrophages, a component of the innate immune system, that are able to then proliferate and respond, through phagocytosis, much more rapidly to subsequent exposure to rabies.
All of these explanations describe mechanisms that could have resulted in the treatment's effectiveness (excess of course for the "none of these" answer)
None of these explanations describe mechanisms that could have resulted in the treatment's effectiveness
By injecting the pulverized rabies pathogens, you created adaptive plasma macrophages that are able to generate antibodies against rabies antigens and are now able to do so rapidly when exposed to viable rabies infections. The immunized animal's immune system can now quickly mount a macrophage generated antibody defense to fight off the rabies before the infection can take any significant hold in the exposed animal.
No animals got rabies from your vaccine because you effectively destroyed the viability of the rabies pathogens before injecting them into your animal. Rabies glycoprotein antigens from the pulverized samples elicited an immune response when B cell antigen receptors recognized the injected antigens and stimulated a proliferation of B cells. These B cells produced plasma B cells that generate antibodies against the rabies antigens, and memory B cells were also generated. This resulted in basically priming the immunized animal's immune system such that when subsequently exposed to actual rabies, the immunized animal's immune system can quickly mount an antibody defense to fight off the rabies before the infection can take any significant hold in the exposed animal.