Fill in the blank (_) in the following sentence from the following choices.
Sentence: The mental health of Brian is much worse than William's because _ sees a therapist.

Choice 1: The mental health of Brian is much worse than William's because Brian sees a therapist.
Choice 2: The mental health of Brian is much worse than William's because William sees a therapist.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
2
1.