Explanation

In the AWS Shared Responsibility Model for Amazon RDS:

AWS Responsibility (Security OF the Cloud):

• Managing the underlying server hardware
• Applying patches to the underlying operating system
• Applying minor patches to the database
• Physical security of data centers
• Network infrastructure security

Customer Responsibility (Security IN the Cloud):

• Applying encryption options for the database (correct answer)
• Managing database users and permissions
• Configuring security groups and network access controls
• Implementing database backup and recovery strategies
• Managing application-level security

Why other options are incorrect:

• Option B (Manage underlying server hardware): This is AWS's responsibility in the managed RDS service
• Option C (Apply patches to underlying OS): AWS manages operating system patches for RDS instances
• Option D (Apply minor patches to database): AWS handles database engine patches and updates

Key Concept: With managed services like Amazon RDS, AWS handles the undifferentiated heavy lifting of infrastructure management, while customers focus on their data, applications, and security configurations.