Slack applies OAuth authorization at the API-method level. If an access token does not contain the scope required by the requested Web API operation, Slack rejects the call rather than silently granting additional privileges or returning unauthorized data. A common response is the `missing_scope` error, which indicates that the token lacks the specific scope permissions necessary to complete the operation. Slack's permissions model therefore enforces least privilege: an application's token can perform only the actions authorized through its granted scopes. Adding a scope to app configuration does not automatically upgrade an already issued token; existing installations may need reauthorization when new required scopes are introduced. Slack also does not normally email an administrator merely because an API request lacks a scope. Therefore, B accurately represents Slack's authorization behavior.