ABC Has Three AWS Accounts

Multiple Choice

ABC has three AWS accounts. They have created separate IAM users within each account. ABC wants a single IAM login URL such as https://abc.signin.aws.amazon.com/console/ for use by IAM users in all three accounts. How can this be achieved?

A) Merge all the accounts with consolidated billing
B) Create the S3 bucket with an alias name and use the redirect rule to forward requests to various accounts
C) Create the same account alias with each account ID
D) It is not possible to have the same IAM account login URL for separate AWS accounts