Which of the following can be a part of a CloudFormation stack?

The correct choice, which states that resources defined in a single template can be a part of a CloudFormation stack, highlights the core functionality of AWS CloudFormation. A CloudFormation stack is a collection of AWS resources that you create, update, and delete as a single unit.

Each stack is directly associated with a CloudFormation template, which serves as a blueprint for the stack. This template is in JSON or YAML format and defines the AWS resources and their configurations that will be provisioned as part of the stack. These resources can include a wide variety of AWS services, such as EC2 instances, S3 buckets, RDS databases, IAM roles, and many more.

By using a single template to define multiple resources, you can manage them cohesively, ensuring that all configurations are consistent and can be easily replicated or modified. This intrinsic structure empowers developers and operations teams to efficiently manage infrastructure as code.

In contrast, the other options are limited to specific resources or configurations that do not reflect the breadth of capabilities offered by CloudFormation. For example, stating that only EC2 instances or S3 buckets can be part of a stack inaccurately suggests the limitation of resources available in a stack, which actually supports an extensive range of AWS services beyond just these two