Final answer:
An endemic species is found only in a specific, usually restricted, geographic area, like the Venus flytrap in North and South Carolina, contrasting with generalist species such as the raccoon in North and Central America.
Step-by-step explanation:
What Defines an Endemic Species?
An endemic species is one which is naturally found only in a specific geographic area that is usually restricted in size. This is in contrast to generalist species, which are found in a wide variety of geographic areas. For example, the Venus flytrap (Dionaea muscipula) is an endemic species to a small area in North and South Carolina, while the raccoon (Procyon spp) is a generalist species, native to most of North and Central America.
To answer the multiple-choice question, the correct option is: a. a small geographic range, since an endemic species is one that exists naturally in such a range, and is not defined by the other options listed such as a specialized diet, parasitic lifestyle, or symbiotic lifestyle.
Ecologists interested in biogeography study the distribution of endemic species, like the koala found only in Australia, and understand their importance to biodiversity, especially in biodiversity hotspots which often feature a large number of such species.