The Security team at AnyCompany discovers that some employees have been using individual AWS accounts that are not under the control of AnyCompany. The team has requested that those individual accounts be linked to the central organization using AWS Organizations.
Which action should a SysOps Administrator take to accomplish this?

A. Add each existing account to the central organization using AWS IAM.
B. Create a new organization in each account and join them to the central organization.
C. Log in to each existing account and add them to the central organization.
D. Send each existing account an invitation from the central organization.