If an administrator were unable to update references to objects in other domains in the forest, this might indicate a failure of the ____________

a. RID master
b. PDC emulator
c. Schema master
d. Infrastructure master

D. If the infrastructure master were to fail, an administrator would notice a problem if she attempted to update references to objects in other domains. She would be unable to move or rename a large number of accounts. Users might be unable to access objects in other domains because their references would not be updated.