What is the MOST likely cause of the 5-minute connection outage?

A Database Specialist is troubleshooting an application connection failure on an Amazon Aurora DB cluster with multiple Aurora Replicas that had been running with no issues for the past 2 months. The connection failure lasted for 5 minutes and corrected itself after that. The Database Specialist reviewed the Amazon RDS events and determined a failover event occurred at that time. The failover process took around 15 seconds to complete.

What is the MOST likely cause of the 5-minute connection outage?
A . After a database crash, Aurora needed to replay the redo log from the last database checkpoint
B . The client-side application is caching the DNS data and its TTL is set too high
C . After failover, the Aurora DB cluster needs time to warm up before accepting client connections
D . There were no active Aurora Replicas in the Aurora DB cluster

Answer: C