Please answer the following question: Fact 1: Lungs are used for breathing air by land animals. Fact 2: Land Animals Land animals have four limbs. Given the two facts above, answer the question "Lungs are used for breathing air by animals with what?" with the following options: - unidirectional - exoskeleton - contracting - fins - four limbs - gills - kinetic energy - eight eyes
A:
four limbs