Fill in the blank (_) in the following sentence from the following choices.
Sentence: Monica was able to afford a luxury vacation, but Laura stayed home, because _ earned a much smaller salary.

Choice 1: Monica was able to afford a luxury vacation, but Laura stayed home, because Monica earned a much smaller salary.
Choice 2: Monica was able to afford a luxury vacation, but Laura stayed home, because Laura earned a much smaller salary.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
1
2.