Calls made using the OPTIONS method return information in the header about what other HTTP methods are available for the given resource. In this context, 'available' specifically means what API calls the current user would be able to make without receiving a 403 (Access Denied) or 404 (Resource not found) response, nothing more. A comma separated list of HTTP methods is specified in the "Allow" header of the response. There is no response body. For example, an OPTIONS call to:

https://api.schoology.com/v1/users/5

Would return something like:

 HTTP/1.1 200 OK
 Date: Wed, 12 Nov 2010 23:11:02 GMT
 Allow: DELETE, GET, PUT
 X-Schoology: API
 Vary: Accept-Encoding
 Content-Length: 0
 Content-Type: text/html; charset=utf-8

Which states that the current user can DELETE, GET and PUT user with ID 5