Fill in the blank (_) in the following sentence from the following choices.
Sentence: Kyle will be able to retire a lot earlier than Adam because _ is further behind in their career.

Choice 1: Kyle will be able to retire a lot earlier than Adam because Kyle is further behind in their career.
Choice 2: Kyle will be able to retire a lot earlier than Adam because Adam is further behind in their career.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
2
2.