Question: What is the Command-Code field value for a STA command, as defined in IETF RFC 6733 (DIAMETER BASE), and what does it indicate?
Option 1: 274, indicating an STR command
Option 2: 275, indicating a response to an STR command
Option 3: 276, indicating a session termination request
Option 4: 277, indicating a session establishment request
Explanation: The STA command is indicated by the Command-Code field set to 275 and the 'R' bit cleared in the Command Flags field. This indicates that the STA command is sent in response to an STR command, as defined in IETF RFC 6733 (DIAMETER BASE).