[单选题]
1. Why are phagocytes regarded as a compone3 /m0m0k8 2qg; ccxr ogiw+cmvnt of the innate immune sys t8s(uld hf/9ftem?
A. They are effective against all pathogens.
B. Their method of action does not adapt to pathogenic infections
C. They are found in invertebrates and vertebrates.
D. They can destroy pathogens and damaged body cells.