Right answer:
cree en
Él is the subject pronoun for the third person singular in masculine form whose translation in English is he. On the other hand, cree is the conjugation of the verb creer that matches the third person singular in the simple present tense. This tense is one of two simple past tenses. It is used to describe actions that took place or were completed at a certain point in the past. So Él cree en las leyendas means He believes in legends.