Fill in the blank (_) in the following sentence from the following choices.
Sentence: The sound of the tickling clock was audible in the room because the _ is loud.

Choice 1: The sound of the tickling clock was audible in the room because the room is loud.
Choice 2: The sound of the tickling clock was audible in the room because the clock is loud.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
2
2.