Passage: "During a vehicle pursuit, CHP policy requires the primary unit to maintain radio communication, report speed and direction every block, and disengage if the risk to the public outweighs the need to apprehend." According to the passage, the primary unit must disengage when:

1. The pursuit lasts more than one minute
2. The risk to the public outweighs the need to apprehend
3. The suspect changes lanes
4. Backup arrives