Fact 1: Playing is one way mammals and other animals learn how to behave. Fact 2: Cats are Mammals that Shed Dogs are Mammals that Wag their tails. Given the two facts above, playing is one way what learn how to behave?

Pick from:
-- otters;
-- bacteria;
-- cats;
-- bears;
-- ants;
-- grass;
-- humans;
-- bats;
The answer is:
cats