Scientists are trying to find the causative agent for a new disease in chicken. They grow a culture of what they think is the causative agent. They then inoculate a large group of healthy representative chicken with the agent, but none of the chicken become ill. Applying the Germ Theory of Disease, which of the following could explain the results (choose all correct answers)?
A. They isolated resident microbiota (look in your textbook for definition)
B. The suspected causative agent is found in healthy chickens.
C. The true causative agent is not an infectious disease.
D. The suspected causative agent is an infectious disease.