Question: What is the primary purpose of storing MMS user preferences information on a Universal Subscriber Identity Module (USIM) for an MMS User Agent?
Option 1: To enforce network operator's default settings for all MMS transmissions.
Option 2: To provide user assistance in preparing terminal-originated Multimedia Messages (MMs) with default parameter values.
Option 3: To store a history of all sent and received MMS messages on the USIM.
Option 4: To bypass user input for MMS connectivity settings, always using USIM defaults.
Explanation: The primary purpose of storing MMS user preferences on a USIM is to assist the user in preparing outgoing MMS messages by offering default values for frequently used parameters, thereby streamlining the message preparation process. This aligns with enhancing user experience and efficiency rather than enforcing operator settings, storing message history, or bypassing user input entirely.