Which requirement is explicit in the Circular No. 230 rule on conflict of interest?

1. The practitioner should retain copies of written consent for at least 36 months from the date representation of the client concluded.
2. The practitioner may not represent a client if such representation adversely affects another of the practitioner's clients.
3. The practitioner should send copies of written consents to the SECs office of the chief accountant
4. The practitioner may not represent an attest client if the practitioner is personally conflicted under any circumstances.