Which of the following best describes a role that grants access to use REST services?

The best description of a role that grants access to use REST services is the module role. In Mendix, module roles are specifically designed to provide permissions to access various functionalities within a module, including the ability to interact with REST services. These roles can be finely tuned to allow API access, enabling users to interact with the application through different endpoints according to the permissions set for that module role.

Module roles allow for a more granular control of access rights compared to other roles. This feature is essential for applications that utilize REST services to expose data or functionality for consumption by other applications or services, as it ensures that only authorized users can perform specific actions on the API.

In contrast, other roles such as the guest role and viewer role do not typically have permissions configured to access REST services, as they are generally more restrictive and are meant for limited use cases. The administrator role has broad access but is focused more on management tasks rather than the specific function of using REST services.