Fill in the blank (_) in the following sentence from the following choices.
Sentence: Kenneth taught Jeffrey how to increase the oxygen in the room because _ cares about his health.

Choice 1: Kenneth taught Jeffrey how to increase the oxygen in the room because Kenneth cares about his health.
Choice 2: Kenneth taught Jeffrey how to increase the oxygen in the room because Jeffrey cares about his health.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
1
2.