Two zoogeographical region, separated by high mountain ranges are:
a. Oriental and Australian
b. Palaearctic and Oriental
c. Nearctic and Palaearctic
d. Neotropical and Ethiopian

Hint: As we have learnt that our Earth’s continental mass is divided into six biogeographical realms based on the distribution of birds, these realms constitute eight major zoogeographical regions that possess a characteristic bird’s fauna.

Complete answer:
> Philip Lutley Sclater divided our Earth into six biogeographical realms based on the distribution of Bird’s fauna. He named them as Palaearctic, Nearctic, Neotropical, Ethiopian, Oriental and Australian. And these realms constitute eight major zoogeographical regions that possess a characteristic bird’s fauna namely North Asia, Europe, North America, South America, Africa, Southeast Asia including India, Australia and New Zealand.

> We can discuss them one by one, so let us start with Oriental region, it includes the Southeast Asiatic regions including Indian subcontinent, Southern China, Philippines, Indonesian Islands and Malay. In the east there are rainforests and in the north there are present high mountains. Africa shares 25% of the fauna and the Palaearctic region shares fauna like Hedge-hog, porcupine etc.

> Next is Palaearctic, it is the largest realm of all and stretches from North Asia to foothills of Himalayas of Eurasia north. Accentors from a bird family called Prunellidae are endemic to this region along with Loons, Grouse, Auks and Waxwings.

> Next comes the Nearctic realm which encompasses North America including Central Florida, Greenland and the highlands of Mexico. It is also known as the Head-quarters of Urodels and nearly 39 birds families are found in this region including Hummingbirds, Pelican etc.

> Neotropical realms involve South America, Central America, West Indies and Mexico. It is called the Bird continent as it has a peculiar and striking bird’s fauna including American Ostrich, Tinamus, Ducks etc.

> Ethiopian realm covers Africa and has deserts on the North popularly Sahara Desert and the most popular bird found in this region is two toed Ostrich called Struthio camelus.

> Lastly the Australian realm including Australia, New Zealand and New Guinea and it is popular for the flightless birds like Kiwi which is native to New Zealand only, Emu native to New Guinea and Casso native to Australia.
Out of these, Palaearctic and Oriental realms are separated by high mountain ranges.

Hence, the correct answer is option (B).

Note: Weber drew an imaginary line on a map separating the Oriental and Australian realms and a similar line was postulated by Wallace that separated Asia and a transitional zone between Australia and Asia.