It is called THERAPEUTIC INDEX. Therapeutic index is the comparison of the amount of a particular drug that causes the desired therapeutic effects and the amount that causes toxicity. The index can be low or high. A drug with a low therapeutic index will require only a small increase in dose to produce toxic effects in users.
So the organisms could be classified in the same animal families
In this case, c) mimicry is the answer. In Batesian mimicry in which harmless animals mimic toxic animals. In this case, I assume the milk snake is harmless and the coral snake is venomous. Since the milk snake has a trait similar to deadly coral snake, less animals would eat it thinking it is dangerous. Over time all the milk snake that look like the deadly coral snake would survive leading to evolution by natural selection. This would lead to more and more milk snake mimicking the resemblance of the deadly coral snake.
a) The deadly coral snake has a warning color adaptive radiation. If the question had described the environment and how the snaked adapted to the environment via warning coloration. This would've been correct.
b) cryptic coloration is more about camouflage with the environment. If the question had state how a certain feature help one of the animals blend into the background. This would've been correct.
d) I'm not sure whats different between this and a so i'll consider them both the same.
