The AWS Serverless Application Model (AWS SAM) is an open-source framework specifically designed for building serverless applications. It provides a simplified, shorthand syntax as an extension of AWS CloudFormation to define serverless resources like AWS Lambda functions, Amazon API Gateway APIs, and Amazon DynamoDB tables. Developers use a YAML or JSON template file (template.yaml) to model their application. During deployment, the AWS SAM CLI transforms this simplified template into a standard, more verbose AWS CloudFormation template, which is then used to provision the resources. This directly matches the developer's need to define serverless resources in YAML for a CloudFormation-based deployment.

A. CloudFormation serverless intrinsic functions: This is not a recognized AWS term. While CloudFormation has intrinsic functions, there is no specific category named "serverless intrinsic functions."

B. AWS Elastic Beanstalk: This is a Platform as a Service (PaaS) for deploying and scaling web applications, not a framework for defining serverless infrastructure in a YAML template.

D. AWS Cloud Development Kit (AWS CDK): The AWS CDK uses familiar programming languages (like Python, TypeScript, or Java) to define cloud infrastructure, not YAML directly. It synthesizes a CloudFormation template from the code.

1. AWS Serverless Application Model (AWS SAM) Developer Guide: In the section "What is the AWS Serverless Application Model (AWS SAM)?"

it states

"The AWS Serverless Application Model (AWS SAM) is an open-source framework that you can use to build serverless applications on AWS... With SAM

you define your application resources in a YAML or JSON template."

2. AWS CloudFormation User Guide: The "Intrinsic function reference" section lists all available intrinsic functions. It does not include a category or specific functions called "serverless intrinsic functions."

3. AWS Cloud Development Kit (AWS CDK) Developer Guide: The "What is the AWS CDK?" section clarifies

"The AWS Cloud Development Kit (AWS CDK) is an open-source software development framework to define your cloud application resources using familiar programming languages."

4. AWS Elastic Beanstalk Developer Guide: The "What is AWS Elastic Beanstalk?" section describes it as a service to "deploy and manage applications in the AWS Cloud without worrying about the infrastructure that runs those applications

" highlighting its role as a PaaS

not a templating tool.