A web-startup runs its very successful social news application on Amazon EC2 with an Elastic Load Balancer, an Auto-Scaling group of Java/Tomcat application-servers, and DynamoDB as a data store. The main web application best runs on m2 x large instances since it is highly memory-bound. Each new deployment requires semi-automated creation and testing of a new AMI for the application servers which takes quite a while and is therefore only done once per week. Recently, a new chat feature has been implemented in node.js and waits to be integrated into the architecture.

Answer options:

A.Create one AWS Ops Works stack, create one AWS Ops Works layer and create one custom recipe.
B.Create one AWS Ops Works stack, create two AWS Ops Works layers and create one custom recipe.
C.Create two AWS Ops Works stacks, create two AWS Ops Works layers and create one custom recipe.
D.Create two AWS Ops Works stacks, create two AWS Ops Works layers and create two custom recipes.

Answer - B
You can just have one Opswork stack and multiple layers, one for Node.js and the other for the standard application.
An AWS OpsWorks Stack defines the configuration of your entire application: the load balancers, server software, database, etc. You control every part of the stack by building layers that define the software packages deployed to your instances and other configuration details such as Elastic IPs and security groups. You can also deploy your software onto layers by identifying the repository and optionally using Chef Recipes to automate everything Chef can do, such as creating directories and users, configuring databases, etc. You can use OpsWorks Stacks’ built-in automation to scale your application and automatically recover from instance failures. You can control who can view and manage the resources used by your application, including ssh access to the instances that your application uses.
For more information on Ops work, please visit the below URL
https://aws.amazon.com/opsworks/stacks/faqs/