The correct answer is A. Creating a function URL for the Lambda function and providing it to the third party for the webhook is the most operationally efficient solution. Function URLs provide a built-in HTTPS endpoint for invoking Lambda functions, making it simple and straightforward to integrate with external services. This approach avoids the additional complexity and cost associated with using an Application Load Balancer (ALB), Amazon SNS, or Amazon SQS, which are more suitable for different use cases.