An IT firm is deploying all its production resources using AWS CloudFormation Templates. A complex stack is to be deployed wherein one stack`s output values will be used as an input to another stack in the same group. As a SysOps administrator, you need to create a template for this stack with minimum efforts & the least resources. This template will be used in all further deployments. Also, there is a Security guideline to ensure no information is shared outside the stack. Which of the following is the preferred option to meet this requirement?

Answer options:

A.Use lambda function to export stack values between stack in the same group.
B.Hardcode resource value in stack template to share values between stacks in the same group.
C.Use nested stacks to share information between stacks.
D.Use export function between stacks to have output of a stack as an input of another stack.

Correct Answer: C
A nested Stack can be used to share information within a group of stacks. A nested stack is preferred when information needs to be isolated within the stacks & not share outside to other stacks.
Option A is incorrect as this will incur additional work for the creation of Lambda function.
Option B is incorrect as this will incur additional admin work for inputting values in each template.
Option D is incorrect as export values can be used to share values with other stacks in the same AWS account or region. In the above case, information needs to share within the same group. So using a nested stack will be a better option.
For more information on exporting values between stacks, refer to the following URL-
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-stack-exports.html