An end user (external user account) has been removed from the Users tab in CyberArk...

Privilege Cloud (Shared Services) user access is governed by CyberArk Identity user existence and policy. If the user account is removed, sign-in is blocked and the end-user experience is the standard “unable to sign in / contact administrator” style message, consistent with CyberArk’s end-user troubleshooting guidance when sign-in is blocked by policy/account state.

(Options C and D do not align with Identity-based access control behavior; a removed Identity user should not be able to authenticate successfully.)