You have configured a policy setting in the User Configuration node of a domain GPO and linked the GPO to OU$-$X$.$ Later, you discover you linked it to the wrong OU$,$ so you unlink it from OU$-$X and link it to OU$-$Y$,$ which is correct. A few days later, you find that users in OU$-$X still have the policy setting applied to their accounts. What's the most likely cause of the problem?

a$.$ Group policy settings haven't been refreshed.

b$.$ The policy setting is unmanaged.

c$.$ Users in OU$-$X have an item$-$level target filter configured.

d$.$ The GPO is disabled.