Explanation

Amazon CloudWatch and AWS CloudTrail are the correct services for monitoring and retaining records of account activities related to governance, compliance, and auditing:

Amazon CloudWatch

• Provides monitoring and observability for AWS resources and applications
• Collects and tracks metrics, collects and monitors log files
• Sets alarms and automatically reacts to changes in AWS resources
• Useful for operational monitoring and maintaining compliance

AWS CloudTrail

• Specifically designed for governance, compliance, and auditing
• Records AWS API calls and account activity
• Provides event history of AWS account activity
• Enables security analysis, resource change tracking, and troubleshooting
• Essential for compliance auditing and governance

Why the other options are incorrect:

Amazon GuardDuty: A threat detection service that continuously monitors for malicious activity and unauthorized behavior, but not primarily for activity logging and retention.

AWS Shield: A managed DDoS protection service that safeguards applications running on AWS, not for activity monitoring and auditing.

AWS WAF: A web application firewall that helps protect web applications from common web exploits, not designed for account activity monitoring and retention.