Which of the following resource is used in Cloudformation to create nested stacks

Answer options:

A.AWS::CloudFormation::Stack
B.AWS::CloudFormation::Nested
C.AWS::CloudFormation::NestedStack
D.AWS::CloudFormation::StackNest

Answer - A
The AWS Documentation mentions the following
A nested stack is a stack that you create within another stack by using the AWS::CloudFormation::Stack resource. With nested stacks, you deploy and manage all resources from a single stack. You can use outputs from one stack in the nested stack group as inputs to another stack in the group
For more information on AWS::CloudFormation::Stack resource , please refer to the below link:
http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-stack-exports.html