Your team uses a CloudFormation stack for an application. There are a large amount of AWS resources created in the stack, including Auto Scaling groups, Lambda functions, Security groups and Route 53 domain names, which make the CloudFormation template hard to maintain. You want to divide the template into several parts and inherit the resources. In the meantime, you still want to manage all resources in a single stack. Which of the following options is the most appropriate? 

Answer options:

A.Ensure that the stack template uses the YAML format and uses the “---” symbol to divide the template into several partitions.
B.Use the “AWS::CloudFormation::Stack” resources to divide the stack into several nested stacks.
C.Use the “AWS::CloudFormation::SubStack” resources to create sub-stacks and export the values in the sub-stacks for other stacks to import.
D.Divide the stack into a CloudFormation StackSet by using the “AWS::CloudFormation::StackSet” resource.

Correct Answer: B
Option A is incorrect because the option does not mention how to share resources between different parts, and all resources are still placed into a single template as before.
Option B is CORRECT because, with nested stacks, the whole stack is divided into different stacks. And the outputs from one stack in the nested stack group can be used as inputs to another stack.
Option C is incorrect because the description is wrong as there is no “AWS::CloudFormation::SubStack” resource. Nested stacks should be used instead.
Option D is incorrect because StackSet is used to create stacks across multiple accounts and regions with a single operation. StackSet is not required in this scenario.
Reference:
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-stack-exports.html#output-vs-nested