What would be the HTTP content-type header when a message is optimized using MTOM ? (Choose one)

When MTOM/XOP is used to optimize a SOAP message, it is serialized into a MIME Multipart/Related message using XOP processing. The base64Binary data is extracted from the SOAP message and packaged as separate binary attachments within the MIME message, in a similar manner to e-mail attachments.
The size of the base64Binary data is significantly reduced because the attachments are encoded in binary format. The XML in the SOAP message is then converted to XOP format by replacing the base64Binary data with a special element that references the relevant MIME attachment using a URI.

The modified SOAP message is called the XOP document, and forms the root document within the message. The XOP document and binary attachments together form the XOP package. When applied to the SOAP MTOM specification, the XOP package is a MIME message in MTOM format.

The root document is identified by referencing its Content-ID in the overall content-type header of the MIME message. Here is an example of a content-type header:

Content-Type: Multipart/Related; boundary=MIME_boundary;
type=”application/soap+xml”; start=””

http://www.ibm.com/support/knowledgecenter/SSGMCP_5.2.0/com.ibm.cics.ts.webservices.doc/mtomxop/dfhws_attachments_and_SOAP.html

A is correct