It's a Dead Man's Dream. hope this helps :)
D) A central idea is often stated directly, while a theme is usually only suggested.
Answer:
<u><em>Once a species starts dwindling in numbers, there's a smaller pool of available mates and often a corresponding lack of genetic diversity. This is the reason it's much healthier to marry a complete stranger than your first cousin, since, otherwise, you run the risk of "inbreeding" undesirable genetic traits, like susceptibility to fatal diseases.</em></u>
Explanation: