Every adult male tiger is larger than even the largest female tiger. In groups of tigers, any adult male tiger will dominate any female tiger. If the statements above are true, which one of the following must, on the basis of them, be true? ['Size is the most important factor in deter- mining dominance among tigers.', 'Some large female tigers dominate young male tigers.', 'Some lions are more ferocious than tigers.', 'If a female tiger dominates a male of the species, the male is not an adult.']