What is the purpose of a 'preemption delay timer' in an EVP system?

1. To delay the response to all preemption calls by a fixed amount
2. To provide a programmable delay between receiving the preemption call and initiating the preemption sequence, allowing for low-priority calls to be confirmed
3. To delay the return to normal operation after preemption ends
4. To delay the activation of the emergency vehicle's siren