Which of the Following Occurred During the Coevolution of Humans

Which of the following occurred during the coevolution of humans and pathogens that cause disease?

A) The pathogens produce substances that suppress our immune system.
B) Our immune system can destroy the pathogens before they cause disease.
C) Pathogens have become less infectious.
D) Our immune system no longer sees the pathogen as foreign.
E) Pathogens have developed their own immune system to counteract ours.