Answer:
Populations have genetic variation.
The environment changes.
Organisms must have specific traits in order to survive and reproduce.
Explanation:
Natural selection provides an advantage during an adverse condition for organisms that have a rich genetic variation in their population.
Also, environmental changes induced natural selection whereby organisms must adapt to changes around them.
For organisms to survive, they must have specific traits that gives them a competitive reproductive advantage.
Covalent bond forms between the oxygen and hydrogen atoms.
(I attached a picture that could help)
-Hope that helps,
Good luck!
The answer is C ionic bonds