Which database implementations will meet these requirements?
(Choose two.)
Amazon Redshift
Amazon DynamoDB
Amazon RDS for MySQL
MySQL-compatible Amazon Aurora Multi-AZ
Amazon RDS for SQL Server Standard Edition Multi-AZ
Explanations:
Amazon Redshift is a data warehouse solution, not a relational database for transactional workloads, and is not designed for high availability in the context of a mission-critical web application.
Amazon DynamoDB is a NoSQL database, which is not suitable for relational workloads requiring SQL or transaction management for mission-critical web applications.
Amazon RDS for MySQL can provide high availability with Multi-AZ, but it is not as fault-tolerant or scalable as Amazon Aurora.
MySQL-compatible Amazon Aurora Multi-AZ is a highly available and fault-tolerant database that automatically replicates data across multiple AZs, making it ideal for mission-critical web applications.
Amazon RDS for SQL Server Standard Edition Multi-AZ provides high availability and failover capabilities with automatic backups and replication to multiple availability zones.
I calculate that the answer is:
MySQL-compatible Amazon Aurora Multi-AZ