Oracle Integration Cloud (OIC) has a default payload size limit of 10 MB for synchronous, in-memory processing. To handle files larger than this limit, OIC must use a streaming approach where the file is written directly to a temporary storage area (the stage) without being fully loaded into memory.

Options A, C, and D represent valid streaming mechanisms. The REST Adapter supports receiving large files via multipart attachments (A) and downloading large files from endpoints by streaming the response to stage (D). The SOAP Adapter supports receiving large files as MTOM attachments (C), which is the standard for handling large binary data with SOAP. In all three cases, the file is made available in the OIC stage area for subsequent processing by the Stage File action.

B. Sending a large file as Base64-encoded data within the SOAP body is not viable, as the entire SOAP message, including the encoded data, is subject to the 10 MB payload limit.

E. This describes a logically flawed process. The FTP adapter connects to external FTP/sFTP servers, not the internal OIC file server (stage), to download files.

1. Oracle Integration Generation 2 Documentation, Service Limits: "The maximum size for a message payload that can be processed is 10 MB. This limit does not apply to files that are staged in Oracle Integration, which can be up to 1 GB in size." This reference establishes the core 10 MB constraint and the role of staging for larger files.

Source: Oracle Help Center, Service Limits for Oracle Integration Generation 2, Section: "Message Payload Size".

2. Oracle Integration REST Adapter Documentation (for option A): The REST Adapter can be configured as a trigger to accept multipart/form-data. "When you select Multipart Attachment, the request payload is not parsed. Instead, the request payload is directly available for you to stage and process." This confirms the streaming approach for multipart uploads.

Source: Oracle Help Center, Using the REST Adapter with Oracle Integration, Chapter: "Add the REST Adapter to an Integration", Section: "Configure the Request Page".

3. Oracle Integration SOAP Adapter Documentation (for option C): The SOAP Adapter explicitly supports MTOM for handling large attachments. "Select this checkbox [Download Attachments (MTOM)] to download attachments with an MTOM-optimized format." This is the standard mechanism for streaming large files with SOAP.

Source: Oracle Help Center, Using the SOAP Adapter with Oracle Integration, Chapter: "Add the SOAP Adapter to an Integration", Section: "Configure the Operations Page".

4. Oracle Integration REST Adapter Documentation (for option D): When invoking an external REST API, the adapter can be configured to stream the response. "Select this option [Select to Download the File] to download a file from an endpoint. The response from the endpoint is not parsed, but is written to a file in a stage location."

Source: Oracle Help Center, Using the REST Adapter with Oracle Integration, Chapter: "Add the REST Adapter to an Integration", Section: "Configure the Basic Info Page".