The antecedent is Bears. Antecedent means something that precedes something else. In language, it is word that a pronoun refers back to. Since the pronoun replaces the noun, it has to agree in number. So, if the antecedent, or word that comes before, is singular, then the pronoun that takes it place must be singular as well. Since the only thing mentioned twice is the bears and both uses are plural, the answer is Bears.
