Question: What is the primary purpose of the `CatGetInKey` function in the context of (U)SIM API?
Option 1: To update the IconIdentifier based on user input
Option 2: To issue a proactive GET INKEY command and parse the terminal response to update output key parameters
Option 3: To set default reply values for input prompts on the terminal
Option 4: To change the DCS (Data Coding Scheme) value for outgoing messages
Explanation: The `CatGetInKey` function is designed to initiate a proactive GET INKEY command, process the response from the terminal, and if successful, update the output key parameters with the parsed results, aligning with common telecom practices for secure user input handling at the SIM card level.