Question: What is the valid range for the length of a PIN2 when changing it on a Universal Subscriber Identity Module (USIM) application?
Option 1: Between 3 and 6 digits
Option 2: Between 4 and 8 digits
Option 3: Exactly 5 digits, no more or less
Option 4: Between 2 and 12 digits
Explanation: The correct answer is based on the standard specification for USIM applications, where security and uniformity in user authentication are crucial. A PIN2 length of between 4 and 8 digits strikes a balance between being secure (long enough to prevent easy guessing) and user-friendly (short enough to be easily memorable). This range supports various user preferences while maintaining a level of security, which is a key aspect of telecom services.