The following question, consist of two words each that have a certain relationship to each other, followed by four lettered pairs of words. Select the lettered pair that has the same relationship as the original pair of words: Rat : Cat :: Worm : ?

The answer is: B. Earth

In the original pair, “rat” is a prey animal and “cat” is a predator animal that hunts rats. In the answer pair, “worm” is a prey animal and “earth” is a habitat where worms live.

Option A, “fishing”, is incorrect because fishing is an activity that humans do, not an animal that preys on worms. Option C, “bird”, is incorrect because birds are not predators of worms. Option D, “silk”, is incorrect because silk is a product that is made by worms, not an animal that preys on them.