Fill in the blank (_) in the following sentence from the following choices.
Sentence: Rebecca borrowed a measuring tape from Carrie because _ was building a new deck outside.

Choice 1: Rebecca borrowed a measuring tape from Carrie because Rebecca was building a new deck outside.
Choice 2: Rebecca borrowed a measuring tape from Carrie because Carrie was building a new deck outside.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
1
1.