Premise: The killer whale or orca ( Orcinus orca ) is a toothed whale belonging to the oceanic dolphin family , of which it is the largest member . Killer whales are considered a cosmopolitan species , and can be found in each of the world 's oceans in a variety of marine environments , from Arctic and Antarctic regions to tropical seas .
Hypothesis: Killer whales are in oceans.
Label: ENTAILMENT