Although they belong to entirely different classes of animals, sharks (fish) and dolphins (mammals) share fundamental _______ their body shapes, such as streamlined torsos and dorsal fins—traits that these distinct species developed independently to navigate the hydrodynamic challenges of the ocean.
Which choice completes the text with the most logical and precise word or phrase?
origins of
anxieties about
symptoms of
resemblances to
Correct Answer: D
Choice D is the best answer. The text lists physical traits (fins, streamlined bodies) that sharks and dolphins share despite being unrelated. Therefore, they share fundamental "resemblances to" each other.
Choice A is incorrect because they have different evolutionary origins (fish vs. mammal). Choice B is incorrect because the text discusses physical traits, not emotional "anxieties." Choice C is incorrect because traits are not "symptoms" of the other animal; they are parallel adaptations.