What happens when an internal user is configured with an external identity store for authentication, but an engineer uses the Cisco ISE admin portal to select an internal identity store as the identity source?
A. Authentication is redirected to the internal identity source.
B. Authentication is granted.
C. Authentication fails.
D. Authentication is redirected to the external identity source.
Answer is C
https://www.cisco.com/c/en/us/td/docs/security/ise/2-3/admin_guide/b_ise_admin_guide_23/b_ise_admin_guide_23_chapter_011010.html
C. Authentication fails.