Species evolve over time based on their environment.
If part of a group of a species gets isolated into a new environment, then both species (the initial environment and the new one) will evolve differently because of their different environments and in result become different.
So since they both evolve differently based on their different surroundings, the group that was isolated becomes a new species.
It's B
Hope that helps, Good luck! (:
The Sun<span> is the major </span>source of energy<span> for </span>organisms<span> and the ecosystems of which they are a part. Producers, such as plants and algae, use </span>energy<span> from sunlight to make food </span>energy<span> by combining carbon dioxide and water to </span>form<span> organic matter. This process begins the flow of </span>energy<span> through almost </span>all<span> food webs.</span>
