A is the correct answer https://cloud.google.com/blog/products/databases/introducing-cloud-sql-serverless-exports

A: https://cloud.google.com/blog/products/databases/introducing-cloud-sql-serverless-exports Serverless exports enables you to export data from your MySQL and PostgreSQL database instances without any impact on performance or risk to your production workloads.

A. Minimal operational overhead eliminates B and C. Minimal risk to production workloads eliminates D. That leaves A. Least amount of work and doesn't impact the primary instance.

Cloud SQL backups are incremental. They contain only data that changed after the previous backup was taken. Your oldest backup is a similar size to your database, but the sizes of subsequent backups depend on the rate of change of your data. When the oldest backup is deleted, the size of the next oldest backup increases so that a full backup still exists.

With serverless export, Cloud SQL creates a separate, temporary instance to offload the export operation. Offloading the export operation allows databases on the primary instance to continue to serve queries and perform operations at the usual performance rate. BUT is is export (logical backup) and will never be incremental. and the recovery is slow. for 5TB server is it not an option. (only for mini databases). I believe The better option is C

A: Use Cloud SQL serverless exports. Serverless exports enables you to export data from your MySQL and PostgreSQL database instances without any impact on performance or risk to your production workloads. Cloud SQL exports, which offer portable data formats (SQL, CSV), can be triggered anytime and are written to Cloud Storage buckets that you control.

https://cloud.google.com/sql/docs/mysql/import-export#:~:text=Use%20serverless%20export,is%20deleted%20automatically.

Correct Answer - A

Use Cloud SQL serverless exports.