A startup company is using a single AWS account that has resources in a single...

CloudTrail trails can be configured as eithersingle-Regionormulti-Region. A single-Region trail delivers events only for the Region in which it is created; when the company begins using additional Regions, those events will not be logged to the existing S3 destination unless the trail is updated. The least operational overhead is tomodify the existing trailand enablemulti-Regionlogging (that is, configure the trail to “apply to all Regions”). This preserves the current S3 bucket destination, encryption settings, log file validation configuration, IAM roles, and any integrations that already depend on the existing trail name and S3 prefix structure.

Creating a new trail (Options A or C) increases overhead because the engineer would need to manage multiple trails or migrate downstream processes (alerting, Athena tables, SIEM ingestion, retention policies, and lifecycle rules). Option B is not how CloudTrail works—S3 notifications do not cause CloudTrail to collect events from other Regions; CloudTrail must be configured to generate and deliver those logs. Therefore, updating the existing trail to be multi-Region is the simplest and most maintainable fix.