Question: Who is responsible for administering the assignment of Mobile Network Codes (MNCs) under normal circumstances, excluding MCC ranges starting with '90x'?
Option 1: International Telecommunication Union (ITU)
Option 2: National Numbering Plan Administrator
Option 3: Global System for Mobile Communications Association (GSMA)
Option 4: 3GPP Organization
Explanation: According to the principles of allocation and assignment, while the ITU administers MNCs under specific MCC ranges (like 90x) and allocates Mobile Country Codes (MCCs), the general responsibility for assigning Mobile Network Codes (MNCs) falls on each country's National Numbering Plan Administrator. This ensures localized management of network codes within the broader global framework set by the ITU.