Fill in the blank (_) in the following sentence from the following choices.
Sentence: Christine had much better posture than Carrie after years of _ sitting with a slouched back.

Choice 1: Christine had much better posture than Carrie after years of Christine sitting with a slouched back.
Choice 2: Christine had much better posture than Carrie after years of Carrie sitting with a slouched back.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
2
1.