Final answer:
Option (c), The rarity of the Hydrophobic Skunk is due to its lack of sightings, indicating it may be an endemic species in a geographically isolated area. Geographical isolation contributes to species' uniqueness and rarity by preventing genetic exchange and widespread distribution.
Step-by-step explanation:
The rarity of the Hydrophobic Skunk mentioned in the first paragraph is emphasized by its lack of sightings. This suggests that the species may be endemic to a geographically isolated area, leading to its unique characteristics. Endemic species tend to be rare because geographical isolation limits their distribution and prevents them from exchanging genetic information with other populations.
This isolation can arise from the species being confined to a unique environment, which does not share its habitat with related species and cannot exist outside of this particular habitat. Moreover, geographical isolation can result in a lack of evolutionary changes over significant periods of time, ensuring that the unique characteristics of the endemic species are retained.