I can't answer for you, this is a personal question.
Answer:.4.Microorganism X might not be linked to floppy ear disease, because the inoculated mouse remained healthy.5.Microorganism X modified its cell wall structure while being cultured, and is no longer infectious to rabbits.6.A laboratory mouse might not be an appropriate, susceptible host; an experiment with a laboratory rabbit may be needed.
Answer: white blood cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders
hope this helps
I think the best answer is b
