Question: What happens to Type I information in a mobile-terminated call when Type II and Type III information is insufficient for selecting an appropriate interworking function?
Option 1: It is discarded by the network.
Option 2: It is only examined by the destination user.
Option 3: It is also examined by the network.
Option 4: It is sent back to the calling side.
Explanation: In a mobile-terminated call, if Type II and Type III information is not sufficient for selecting an appropriate interworking function, the network will also examine Type I information. This is an exception to the general rule that Type I information is user-to-user and not examined by the network.