Fill in the blank (_) in the following sentence from the following choices.
Sentence: The doors collapsed instantly while the windows were intact, since the _ were weak against the pressure of the wind.

Choice 1: The doors collapsed instantly while the windows were intact, since the doors were weak against the pressure of the wind.
Choice 2: The doors collapsed instantly while the windows were intact, since the windows were weak against the pressure of the wind.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
1
1.