Question: In an SMS message containing a user-defined object (e.g., a small picture) coded according to specifications, what is the primary purpose of starting the message with `<CR>` (Carriage Return)?
Option 1: To indicate the beginning of the User Data Header (UDH)
Option 2: To signal the presence of an embedded image
Option 3: To initiate the rendering of the text in a specific font
Option 4: To prevent the display of 'strange characters' on older terminals not supporting EMS, by overwriting them with the subsequent text
Explanation: Starting an SMS message containing user-defined objects (like images) with `<CR>` is a strategy to ensure compatibility with older terminals that may not support Enhanced Messaging Service (EMS). On such devices, the `<CR>` helps to overwrite any 'unreadable' data (which would otherwise appear as strange characters) with the actual text content of the message, enhancing user experience.