Her immune system is exhibiting the _ line of defense. this defense is part of _ immunity.

last line of defense is the first part.

and the defense is part of her system immunity. this makes sense since the immune system is used to guard against viruses and diseases

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

straight or amphibians are homeothermic to thermal