The Accounts Feed contains:

 The Accounts Feed is a feature of the CyberArk Privileged Access Security Solution that enables the discovery and provisioning of privileged accounts in the environment. The Accounts Feed contains the accounts that were discovered by CyberArk that have not yet been onboarded to the Vault. These accounts are displayed in the Pending Accounts page in the PVWA, where the user can view, analyze, and onboard them according to various criteria. The Accounts Feed helps the user to identify and manage the unmanaged privileged accounts that pose a security risk1.

The other options are not correct, because:

A. Accounts that were discovered by CyberArk in the last 30 days. This is not correct, because the Accounts Feed does not contain all the accounts that were discovered by CyberArk in the last 30 days, but only the ones that have not yet been onboarded. The accounts that were already onboarded to the Vault are not part of the Accounts Feed, but are displayed in the Accounts page in the PVWA1.

C. All accounts added to the vault in the last 30 days. This is not correct, because the Accounts Feed does not contain the accounts that were added to the Vault, but the ones that are waiting to be onboarded. The accounts that were added to the Vault are not part of the Accounts Feed, but are displayed in the Accounts page in the PVWA1.

D. All users added to CyberArk in the last 30 days. This is not correct, because the Accounts Feed does not contain the users that were added to CyberArk, but the accounts that are waiting to be onboarded. The users that were added to CyberArk are not part of the Accounts Feed, but are displayed in the Users page in the PVWA1.

References:

1: Accounts Feed