問題文
A pharmacy chain's register holds one entry for a prescription reminder service: the likelihood that a reminder reaches the wrong household. The entry carries two figures, one recorded before an address verification step was added and one recorded after it. An engineer must say which figure is the inherent one, which is the residual one, and why keeping both is worth the effort. Which explanation is correct?
選択肢
- This distinction applies only to security risk, because privacy risk cannot be reduced by a control, so the register should carry one figure for the reminder service and revisit it only when the law changes.
- That figure before the verification step is the residual one because it is what the register recorded first and therefore describes the state the organization actually observed, while the figure after the step is the inherent one because it reflects the design that is now inherent to the service and will stay in place for as long as the service runs.
- Both figures are residual, because any recorded estimate is made after some controls already exist in the environment, so the register should keep only the later figure and treat the earlier one as history.
- The figure before the verification step is inherent and the figure after it is residual; keeping both shows how much of the reduction depends on that step continuing to work.