Assuming this is in the present tense, the correct answer would be B, "bebe". You can deduce this because Ella is the person doing the action. So the verb must be in the el/ella/usted form. Since the verb beber ends with "-er" conjugating this verb into el/ella/usted form requires to take off the "-er" ending and add "e". Hence, "bebe".
I believe descubrámoslas is correct
683,577 is the population of the city , El paso
