The bottleneck is the database read path, shown by the sudden increase in the RDS ReadLatency metric. Because the application performs more reads than writes, caching frequently requested query results with Amazon ElastiCache is the most direct way to reduce database load and improve response time. Scaling ECS tasks or instances might increase application capacity, but it can also increase read pressure on the database and worsen latency. RDS for MySQL does not use DynamoDB-style read capacity units, so option C is invalid. Increasing ECS task memory helps only if the application containers are memory constrained, which is not indicated. AWS performance guidance identifies caching as a way to improve read latency, read throughput, and efficiency for read-heavy workloads. ( AWS Documentation )

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