Final Answer:
Emails sent or received using a personal or non-official account must be copied or forwarded to your official army email account within 30 days (Option C).
Step-by-step explanation:
Option C (30 days) is the correct choice according to standard military practices. In military organizations, it is imperative to ensure that official communication is conducted through official channels. Transferring emails from personal or non-official accounts to the official army email account within 30 days helps maintain a comprehensive record of communication and ensures that all relevant information is accessible through authorized channels. This practice is essential for maintaining security, accountability, and adherence to military regulations regarding communication protocols.
Option C (30 days) is the answer.