Answer:
c. immune functions.
Explanation:
The endocrine system is involved in the regulation of metabolic rate, body temperature (thermoregulation), tissue development and labor contractions except immune functions.
Studies have shown that no hormone has been identified as being important in the regulation of the immune system. Therefore immune functions is not a regulatory function of the endocrine system.
Although, there have been articles on the endocrine and immune system crosstalk, only a hypothesis of various proteohormones not single hormones have been discovered to act on immunocompetent cells.
Perhaps the answer is "physical characteristics". I am simply making an educated guess, however I do know early philosophers classified organisms into two groups, Plants and Animals, and identified them based on physical characteristics.
Ice is less densw than water (a)
The substances which are less dense than water float on water
The correct answer is 4.) Eventually they become separate species
A process of formation of a new species from an existing species is called speciation.
When a single species changed into two or more separate species, is called speciation. Speciation can take place due to reproductive isolation. In reproductive isolation, the separated species no longer can interbreed among themselves. This is happened due to mating differences, sterility or environmental barriers which finally results into the adaptive splitting into two species.
Try hypothesis. If that's not it, I don't know what else it could be.