Answer:
The AWS service that should be used to deploy a scalable Node.js application is AWS Elastic Beanstalk.
It is a fully managed service that enables users to quickly deploy and run web applications, including Node.js applications, at scale. Elastic Beanstalk provisions resources, manages load balancing, scales resources based on demand, and monitors the application for health and performance. It also supports deployment from a variety of sources, such as AWS CodeCommit, AWS CodePipeline or GitHub. Additionally, Elastic Beanstalk provides integrations with various AWS services, such as Amazon RDS for database management, Amazon S3 for object storage, and Amazon CloudWatch for monitoring and logging.