Answer: Take one manual backup per day, and turn off transaction log retention.

Given the scenario where the Cloud SQL instance is not critical and has a recovery point objective (RPO) of several days, the goal is to minimize ongoing costs. Option A suggests taking no backups and turning off transaction log retention, which aligns with minimizing costs but does not provide any backup, which might be too risky even for a non-critical instance. Option B suggests taking one manual backup per day and turning off transaction log retention, which provides a minimal backup strategy at a lower cost than automated backups. Option C suggests turning on automated backup and turning off transaction log retention, which provides regular backups but at a higher cost than manual backups. Option D suggests turning on both automated backup and transaction log retention, which is the most costly option and exceeds the RPO requirement. Therefore, the best option to minimize costs while still providing some level of backup is Option B.

Author: LeetQuiz Editorial Team