Correct answer - "AWS::Serverless::UserPool" : UserPool applies to the Cognito service which is
used for authentication for mobile app and web. There is no resource named UserPool in the
Serverless Application Model.
Incorrect:
"AWS::Serverless::Function" - This resource creates a lambda function
"AWS::Serverless::Api" - Describes an API Gateway resource. It is useful for advanced use cases
where you want full control and flexibility when you configure your APIs.
"AWS::Serverless::SimpleTable" - Syntax for describing how to create DynamoDB tables