Question

excerpt adapted from the unicorn of the sea by the national oceanic and atmospheric administration. the narwhal is a toothed whale, but it is different from all other toothed whales in that it has no teeth in its mouth. instead, male narwhals have a single, long, straight tooth (or tusk) that protrudes two to three meters out of the upper left jaw. females almost never have a tusk. the tooth grows in a counterclockwise spiral. it is this tusk for which narwhals are best known. there are many legends about the tusk of the narwhal. it is essentially the origin of the myth of the unicorn—european whalers that were in the arctic would catch narwhals and bring tusks back to europe with great stories about what kind of animals the tusks were attached to. but in terms of the biology of the animal, the tusk is actually used for social structure, to establish hierarchies of dominance for the males within narwhal pods. narwhals have a black - and - white mottled skin pattern and are white underneath. the scientific name for these whales, monodon monoceros, means “one tooth, one horn.” not very much is known about narwhals, largely because they are difficult to study. they live in remote places, far from civilization, in a habitat that is dark for one half the year, covered in ice for the other half of the year, and not easy to access. we do know that narwhals have adapted to be one of the deepest diving marine mammals, capable of diving to 3. select the correct answer. which detail best develops the author’s claim that the narwhal is a very unique animal? a. “scientists believe the narwhal’s intense winter feeding period may be an adaptation” b. “they live in remote places, far from civilization, in a habitat that is dark” c. “it is different from all other toothed whales in that it has no teeth in its mouth” d. “narwhals have adapted to be one of the deepest diving marine mammals”

Explanation:

The claim is about the narwhal's uniqueness. Option C directly states its difference from other toothed whales in tooth - structure, which is a unique biological characteristic. Options A, B and D mention other aspects like feeding, habitat and diving ability, but not the most unique feature related to its anatomy as stated in the passage.

Answer:

C. "it is different from all other toothed whales in that it has no teeth in its mouth"