Read the following premise and pick the correct choice. Then, respond with which of the choices is correct.
Premise: Cars moved to the shoulder of the road.

Choice 1: The traffic light turned green.
Choice 2: A screaming ambulance approached.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
2
1. The traffic light turned green is not a likely cause for cars moving to the shoulder of the road. The correct answer is likely to be