What is causing this problem?

A customer reports that when they receive a call over analog trunks, it takes 5 seconds to ring on the target.

What is causing this problem?
A . The system Locale is not configured properly.
B . The high level is set on Incoming Call Route.
C . The ring delay on the system telephony settings is not configured.
D . The IP Office is not receiving the ICLID from PST

Answer: D

Explanation:

References: https://downloads.avaya.com/elmodocs2/ip_office/R3.1/maintenance.pdf