Slack applications declare their requested OAuth permissions through application configuration. These permissions can be configured in the app settings under OAuth & Permissions or represented declaratively in an app manifest. Within a manifest, scopes reside under `oauth_config.scopes`, with separate fields for bot and user scopes. Slack's current platform also supports optional scopes through `bot_optional` and `user_optional`. The scopes determine what actions and data the application's tokens may access after authorization. Browser cookies do not define Slack app permissions, and the Slack CLI's local configuration is not the authoritative location for declaring the application's OAuth scope requirements. Scopes absolutely can—and normally should—be determined before installation so users and administrators can review the requested permissions during OAuth authorization. Therefore, A is correct.