The correct answer is D. A shared layer allows a policy layer to be reused rather than recreated separately in every rule or policy package. In R82, layer properties include a sharing option that lets administrators share a layer with other policies. Official guidance also states that a new policy layer can be configured directly in a specific policy or as a shared policy layer for several policies, and that an Inline Layer can be configured within a specific rule while an Ordered Layer exists as a separate dedicated layer. This supports modular policy design: common controls can be centralized and reused, which improves consistency and reduces administrative duplication. Option A is wrong because NAT translation is configured through NAT rules and NAT settings, not by enabling a shared layer. Option B is the opposite of the real function; sharing increases reuse rather than disabling the layer elsewhere. Option C is also wrong because permissions can restrict who edits a layer, but the “Shared Layer” function itself is about reuse across rules or policies. Reference topics: Policy Layers, Inline Layers, Ordered Layers, Shared Layers, SmartConsole Layer Properties.