A team runs an Amazon API Gateway REST API that invokes an AWS Lambda function. Users report poor performance caused by Lambda cold starts. The team must reduce the Lambda initialization time. Which option accomplishes this?

Enabling provisioned concurrency for the Lambda function is the correct solution because it pre-initializes a specified number of execution environments, ensuring that they are ready to respond immediately to invocations. This directly addresses and mitigates the impact of cold starts, which occur when Lambda needs to initialize a new execution environment. Changing the Lambda configuration to use reserved concurrency only guarantees available concurrency and prevents other functions from consuming it, but it does not pre-warm instances. Increasing the Lambda function’s timeout setting only affects how long a function can run, not its initialization time. Raising the Lambda function’s memory allocation can sometimes reduce execution duration for compute-bound tasks, but it does not directly eliminate cold starts.