A. Both standard and custom HTTP headers can be defined for both the request and the response.

B. File attachments can be accepted as a request option for the trigger interface, but you cannot include attachments as a response to the client.

C. If you select a PUT or POST action (HTTP method), you must define a JSON response payload format.

D. Although you can define both query and template parameters, only template parameters are available for mapping in the mapper because query parameters are considered optional.