Concept:Good ICT security policies strengthen account safety and prevent unauthorised access.Explanation:Re-using an old password is risky because it may already be known to attackers.Frequent password changes keep accounts more secure.Backing up files protects data from loss.Scanning e-mail attachments before opening them prevents virus infections.Therefore, re-using an old password is not a good ICT security policy.Answer:A. Re-use of old password