The relationship between two organisms or species in which both partners derive benefit from each other is known as:

Many parasites have evolved to be $A$ in such a way that both host and the parasite tend to $B$; that is,if the host evolves special mechanisms for rejecting or resisting the parasite,the parasite has to evolve mechanisms to $C$ and neutralize them,in order to be successful with the same host species.
Choose the correct option for $A$,$B$,and $C$.

Which organisms protect themselves from predators by having a bitter taste?

How does the Monarch butterfly acquire the poisonous chemical in its body?

Which of the following is an example of a defense used by plants against herbivores?
$I.$ Production of caffeine,tannin,quinine
$II.$ More production of non-woody tissues
$III.$ Production of hairs,thorns,spines
$IV.$ Production of hormone-like chemicals that interfere with insect metamorphosis
Select the correct pair.

Level of competition between species depends on
$I.$ availability of resources
$II.$ population density
$III.$ group interaction of organisms
Choose the correct combination