A three-tier web application runs in one Availability Zone. The business needs it to survive the loss of a zone, the reporting queries are saturating the database, and the budget will not stretch to a second Region. What is the smallest set of changes that meets all three?

Why this is the answer

The three requirements map to three separate mechanisms: a load balancer across zones for the stateless tier, Multi-AZ for database failover, and a read replica to take the reporting load off the primary. A second Region is explicitly out of budget, a Multi-AZ instance deployment's standby serves no traffic so it cannot absorb reporting, and read replicas are read-only — an application cannot write to them.