Question: What is the primary purpose of the `+CEER` (Extended Error Report) command in the context of GSM/UMTS networks?
Option 1: To provide detailed error information for the latest call setup failure to the Terminal Equipment (TE), enhancing troubleshooting beyond standard PSTN messages.
Option 2: To enable or disable the Radio Link Protocol (RLP) for data transmissions.
Option 3: To select between single and alternating mode for call handling (voice, fax, or data).
Option 4: To set up an asynchronous modem connection with specified data rates.
Explanation: The `+CEER` command is designed to return detailed information about the cause of the latest call setup failure in GSM/UMTS networks, offering more specific error reporting than traditional PSTN messages (e.g., NO CARRIER, BUSY). This enhances the Terminal Equipment's (TE) ability to troubleshoot and understand call failures, leveraging the network's capability to provide richer error context.