Explanation:

Why D (Configure Lambda SnapStart) is correct:

1. Lambda SnapStart is specifically designed for Java 11 (and later) Lambda functions to reduce cold start latency by taking a snapshot of the initialized execution environment after the first invocation.
2. Cost-effectiveness: SnapStart doesn't incur additional costs like provisioned concurrency. It reduces cold starts without requiring you to pay for pre-warmed capacity.
3. Java-specific optimization: Java applications typically have longer cold starts due to JVM initialization, and SnapStart addresses this by reusing snapshots.
4. Matches requirements: The company wants to reduce cold starts and outlier latencies when scaling up, and doesn't have strict latency requirements, making SnapStart ideal.

Why other options are incorrect:

• A (Configure Lambda provisioned concurrency): While this reduces cold starts by keeping functions warm, it's more expensive as you pay for provisioned capacity even when not in use. Not the most cost-effective solution.
• B (Increase the timeout of the Lambda functions): This doesn't address cold start latency at all. Timeout only controls how long a function can run, not startup time.
• C (Increase the memory of the Lambda functions): While more memory can slightly improve performance, it doesn't specifically target Java cold start issues and increases costs without directly addressing the core problem.

Key considerations:

• Lambda SnapStart is free and specifically optimized for Java runtime cold starts
• Provisioned concurrency is better for strict latency requirements but costs more
• The question emphasizes "MOST cost-effectively" which makes SnapStart the clear choice