Question: What is the primary purpose of including the `application/3gpp-partial` media type in the 'Accept' request header of an HTTP GET request in the context of MBMS (Multimedia Broadcast/Multicast Service)?
Option 1: To specify the preferred file format for the response.
Option 2: To indicate support for encrypted file transfers.
Option 3: To signal capability to receive partial file responses.
Option 4: To request a specific quality of service (QoS) for the download.
Explanation: The inclusion of `application/3gpp-partial` in the 'Accept' header informs the server that the client is capable of handling partial file responses, aiding in reducing network load while providing a usable experience in MBMS scenarios.