When the BGP Notification packet Error Code is 2, it indicates that the OPEN message is incorrect. Which of the following error codes is included?

When the BGP Notification packet Error Code is 2, it indicates that the OPEN message is incorrect. Which of the following error codes is included?
A . 1 – Unsupported version number
B . 2 – Wrong peer AS number
C . 3 – Bad BGP RID
D . 4 – Wrong attribute list

Answer: ABC