Which type of natural selection occurs when an intermediate phenotype is favored?

The type of natural selection that occur when intermediate phenotype is favored is called STABILIZING SELECTION.

Explanation:

There are 3 major types of natural selection, these are: stabilizing, directional and diversifying selection.

A stabilizing selection is said to occur when natural selection favors average phenotype by selecting against extreme variations. Stabilizing selection usually leads to decrease in genetic variation of the population concerned.

A good example of stabilizing selection is that of snakes, which have deep green color that blend completely with their environment. This set of snakes will escape from predators more than others in the population, which have color that slightly differ from deep green and which do not blend very well with the environment. Those snakes, whose colour do not blend very well with their environment will get killed more easily by the predators and with time will become extinct while those with colour that blend with the enviroment will survive and produce more offspring.

The extinction of snakes from the population will lead to decrease in genetic variation.

not too sure but maybe in the hot springs.