Which statement about Terraform modules is true?

• A. Modules must be publicly accessible
• B. Modules can be called multiple times
• C. Module is a container for one or more resources
• D. Modules can call other modules

Answer: (D)

Modules in Terraform let you package related configuration into reusable units, and you can nest them to build layered, composable infrastructure. The statement that is true highlights this nesting capability: a module can call another module, enabling you to compose complex setups from smaller, well-tested pieces. This is why it’s the best answer—Terraform supports module blocks inside a module just as in the root configuration, so you can build higher-level abstractions by wiring together multiple modules. For context, you might have a network module that includes its own sub-modules for subnets and security groups, and your top-level configuration calls the network module to bring everything together. The other options aren’t accurate as broad descriptions: modules don’t have to be publicly accessible—they can be local or in a private registry; a module isn’t strictly just a container for resources since it can also hold variables, outputs, and nested modules; and while you can instantiate a module multiple times when you need several similar components, the fundamental capability that makes modules powerful is their ability to call other modules.