Fill in the blank (_) in the following sentence from the following choices.
Sentence: Christopher had a balanced diet but Kevin did not because _ had an excellent knowledge of nutrition.

Choice 1: Christopher had a balanced diet but Kevin did not because Christopher had an excellent knowledge of nutrition.
Choice 2: Christopher had a balanced diet but Kevin did not because Kevin had an excellent knowledge of nutrition.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
1
2.