Fill in the blank (_) in the following sentence from the following choices.
Sentence: Rebecca studied a lot more than Elena during the whole semester. _ failed the exam.

Choice 1: Rebecca studied a lot more than Elena during the whole semester. Rebecca failed the exam.
Choice 2: Rebecca studied a lot more than Elena during the whole semester. Elena failed the exam.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
2
2. The sentence is about Rebecca's superior studying habits, not her failure.