A Team Has an Application That Detects New Objects Being

A team has an application that detects new objects being uploaded into an Amazon S3 bucket. The uploads trigger AWS Lambda function to write object metadata into an Amazon DynamoDB table and an Amazon RDS for PostgreSQL database. Which action should the team take to ensure high availability?

A) Enable Cross-Region Replication in the S3 bucket.
B) Create a Lambda function for each Availability Zone the application is deployed in.
C) Enable Multi-AZ on the RDS for PostgreSQL database.
D) Create a DynamoDB stream for the DynamoDB table.