Answer: The correct answer is- B) Ecosystem.
Ecosystem can be described as a group of living organisms present in a particular area that are interacting with each other as well as the non living components of that environment.
In other words, it is the interaction between biotic ( living such as plants and animals) and abiotic ( non living such as temperature, air, water) components of an environment.
Example- Pond ecosystem, lake ecosystem.
Natural selection is the right answer hope this helps.
When bonding occurs a new substance with new properties is formed.
An atom that gains a negative electron, it becomes a negative ion. If it loses an electron it becomes a positive ion. Some atoms lose electrons and become positive ions. Others gain electrons and become negative ions.
Reactants of photosynthesis include light energy, H2O, and CO2. So I would imagine it’s H2O and CO2