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According to paragraph 1, which of the following is true of the cost of locomotion? A. For humans, the cost of running is lower than the cost of swimming. B. The type of locomotion that comes most naturally to an animal is also the type of locomotion that is least expensive. C. The more metabolic energy required for locomotion, the more expensive the locomotion is considered to be. D. The faster a particular form of locomotion is, the more metabolic energy it requires.