Two species of sea urchins live practically side-by-side in sandy bottoms. The two species appear to have the same diet: drift seaweeds and other bits of organic matter. They can live in the same environment without competing.
As it compels them to live in the same environmental surroundings so the characteristics of living nature also get developed as their current following situation that's helping them to get the same food & habitat.
Two things that INCREASE population, would be an increase in leisure space. Another is if the area is sustainable for life. Two things that would DECREASE population, would be a scarcity of any required resources. A decrease in space, and not a sustainable area.
I'm not completely sure, but I'm fairly certain that the answer is B.
The answer would be chromosomes
Answer: I think the answer is C.
Explanation: