You notice form syslog message that backup power supply down, what next step ?

[PlAwAnSaI]

During a review of syslog messages, you notice that the backup power supply in router A is down. According to the ITILv3 framework, what would be your next step?

A. Inform your escalation contact.
B. Open a problem ticket.
C. Schedule a maintenance window.
D. Open an incident ticket.