AZ-900 Practice Question 97: Policy Exemption Single Resource

An Azure Policy exemption is built for exactly this: it's used "to exempt a resource hierarchy or an individual resource from evaluation of initiatives or definitions," while the resource still "counts toward overall compliance" instead of disappearing from reporting. An exemption targets a specific policyAssignmentId (optionally naming individual policy definitions within an initiative) and supports an optional expiresOn date, after which the exemption is no longer honored, matching the 90-day, single-resource, assignment-unchanged requirement precisely.

Option A is wrong because a resource lock only blocks accidental delete or modify operations; it has no effect on Azure Policy evaluation or compliance reporting. Option B is wrong because creating a new initiative without the rule doesn't remove the *existing* assignment from applying to the storage account; both would still apply, and unassigning or editing the original assignment would weaken it for every storage account, not just this one. Option D is wrong because moving a subscription into its own management group is a heavyweight structural change that affects everything else in that subscription too, and doesn't include a time-bound expiration mechanism the way an exemption does.

Reference: Details of the policy exemption structure