Question: In a 5G network, what is the primary purpose of including the replayed security capabilities of the User Equipment (UE) in the SECURITY MODE COMMAND sent by the Mobility Management Entity (MME)?
Option 1: To enable the UE to select its preferred security algorithm for encryption.
Option 2: To facilitate the MME's load balancing across different security protocols.
Option 3: To prevent 'bidding down' attacks by ensuring the use of the highest supported security capabilities by both the UE and the network.
Option 4: To inform the UE about the network's current security threats and vulnerabilities.
Explanation: Including the replayed security capabilities of the UE in the SECURITY MODE COMMAND is a security measure to prevent 'bidding down' attacks. By ensuring the MME reflects the UE's full security capabilities, the network guarantees that the highest possible security level mutually supported is utilized, thwarting attempts to downgrade security.