Question: In a Public Land Mobile Network (PLMN), when a call attempt to a B number fails due to 'Unobtainable destination - permanent/long term' reasons, what is the maximum number of repeat call attempts (n) allowed before the B number is blacklisted by the Mobile Terminal (MT)?
Option 1: n = 5
Option 2: n = 8
Option 3: n = 1
Option 4: n = 10
Explanation: For 'Unobtainable destination - permanent/long term' categories, the maximum number of call repeat attempts (n) before blacklisting a B number is 1, to prevent persistent attempts to unreachable destinations, conserving network resources and reducing unnecessary traffic.