A loan account is classified as a Non-Performing Asset (NPA) when interest or principal installment remains overdue for more than which duration?

The Large Exposure Framework (LEF) norms prescribed by the RBI primarily aim to prevent:

Which of the following is a key prudential reason for a bank to require a No-Objection Certificate (NOC) from the existing lending bank before opening a Current Account for a borrower with high credit exposure?