What does every successful Slack Web API JSON response typically include?

Slack Web API responses conventionally include a top-level Boolean `ok` property indicating whether the requested operation succeeded. A normal successful response contains `"ok": true` together with any method-specific data, such as a user object, channel information, timestamps, or other returned values. When an API operation fails, Slack generally returns `"ok": false` together with an `error` field identifying the failure condition. Slack explicitly advises callers to evaluate the `ok` value rather than assuming that a syntactically valid response represents success. For example, the official `users.info` method documentation shows a successful response containing `"ok": true` and an unsuccessful response containing `"ok": false`. Slack Web API operations do not normally return CSV files, redirects, or HTML documents as their standard JSON success response. Therefore, A is correct.